diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index b1c1a08c..f39c4c04 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -1,3246 +1,3254 @@
 /**
  * Client UI Javascript for the Calendar plugin
  *
  * @version @package_version@
  * @author Lazlo Westerhof <hello@lazlo.me>
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2010, Lazlo Westerhof <hello@lazlo.me>
  * Copyright (C) 2012, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 // Roundcube calendar UI client class
 function rcube_calendar_ui(settings)
 {
     // extend base class
     rcube_calendar.call(this, settings);
     
     /***  member vars  ***/
     this.is_loading = false;
     this.selected_event = null;
     this.selected_calendar = null;
     this.search_request = null;
     this.saving_lock;
 
 
     /***  private vars  ***/
     var DAY_MS = 86400000;
     var HOUR_MS = 3600000;
     var me = this;
     var gmt_offset = (new Date().getTimezoneOffset() / -60) - (settings.timezone || 0) - (settings.dst || 0);
     var client_timezone = new Date().getTimezoneOffset();
     var day_clicked = day_clicked_ts = 0;
     var ignore_click = false;
     var event_defaults = { free_busy:'busy', alarms:'' };
     var event_attendees = [];
     var attendees_list;
     var resources_list;
     var resources_treelist;
     var resources_data = {};
     var resources_index = [];
+    var resource_owners = {};
     var freebusy_ui = { workinhoursonly:false, needsupdate:false };
     var freebusy_data = {};
     var current_view = null;
     var exec_deferred = bw.ie6 ? 5 : 1;
     var sensitivitylabels = { 'public':rcmail.gettext('public','calendar'), 'private':rcmail.gettext('private','calendar'), 'confidential':rcmail.gettext('confidential','calendar') };
     var ui_loading = rcmail.set_busy(true, 'loading');
 
     // general datepicker settings
     var datepicker_settings = {
       // translate from fullcalendar format to datepicker format
       dateFormat: settings['date_format'].replace(/M/g, 'm').replace(/mmmmm/, 'MM').replace(/mmm/, 'M').replace(/dddd/, 'DD').replace(/ddd/, 'D').replace(/yy/g, 'y'),
       firstDay : settings['first_day'],
       dayNamesMin: settings['days_short'],
       monthNames: settings['months'],
       monthNamesShort: settings['months'],
       changeMonth: false,
       showOtherMonths: true,
       selectOtherMonths: true
     };
 
     /***  imports  ***/
     var Q = this.quote_html;
     var text2html = this.text2html;
     var event_date_text = this.event_date_text;
     var parse_datetime = this.parse_datetime;
     var date2unixtime = this.date2unixtime;
     var fromunixtime = this.fromunixtime;
     var parseISO8601 = this.parseISO8601;
     var init_alarms_edit = this.init_alarms_edit;
 
 
     /***  private methods  ***/
 
     // same as str.split(delimiter) but it ignores delimiters within quoted strings
     var explode_quoted_string = function(str, delimiter)
     {
       var result = [],
         strlen = str.length,
         q, p, i, char, last;
 
       for (q = p = i = 0; i < strlen; i++) {
         char = str.charAt(i);
         if (char == '"' && last != '\\') {
           q = !q;
         }
         else if (!q && char == delimiter) {
           result.push(str.substring(p, i));
           p = i + 1;
         }
         last = char;
       }
 
       result.push(str.substr(p));
       return result;
     };
 
     // Change the first charcter to uppercase
     var ucfirst = function(str)
     {
         return str.charAt(0).toUpperCase() + str.substr(1);
     };
 
     // clone the given date object and optionally adjust time
     var clone_date = function(date, adjust)
     {
       var d = new Date(date.getTime());
       
       // set time to 00:00
       if (adjust == 1) {
         d.setHours(0);
         d.setMinutes(0);
       }
       // set time to 23:59
       else if (adjust == 2) {
         d.setHours(23);
         d.setMinutes(59);
       }
       
       return d;
     };
 
     // fix date if jumped over a DST change
     var fix_date = function(date)
     {
       if (date.getHours() == 23)
         date.setTime(date.getTime() + HOUR_MS);
       else if (date.getHours() > 0)
         date.setHours(0);
     };
 
     // turn the given date into an ISO 8601 date string understandable by PHPs strtotime()
     var date2servertime = function(date)
     {
       return date.getFullYear()+'-'+zeropad(date.getMonth()+1)+'-'+zeropad(date.getDate())
           + 'T'+zeropad(date.getHours())+':'+zeropad(date.getMinutes())+':'+zeropad(date.getSeconds());
     }
 
     var date2timestring = function(date, dateonly)
     {
       return date2servertime(date).replace(/[^0-9]/g, '').substr(0, (dateonly ? 8 : 14));
     }
 
     var zeropad = function(num)
     {
       return (num < 10 ? '0' : '') + num;
     }
 
     var render_link = function(url)
     {
       var islink = false, href = url;
       if (url.match(/^[fhtpsmailo]+?:\/\//i)) {
         islink = true;
       }
       else if (url.match(/^[a-z0-9.-:]+(\/|$)/i)) {
         islink = true;
         href = 'http://' + url;
       }
       return islink ? '<a href="' + Q(href) + '" target="_blank">' + Q(url) + '</a>' : Q(url);
     }
 
     // determine whether the given date is on a weekend
     var is_weekend = function(date)
     {
       return date.getDay() == 0 || date.getDay() == 6;
     };
 
     var is_workinghour = function(date)
     {
       if (settings['work_start'] > settings['work_end'])
         return date.getHours() >= settings['work_start'] || date.getHours() < settings['work_end'];
       else
         return date.getHours() >= settings['work_start'] && date.getHours() < settings['work_end'];
     };
     
     // check if the event has 'real' attendees, excluding the current user
     var has_attendees = function(event)
     {
       return (event.attendees && event.attendees.length && (event.attendees.length > 1 || String(event.attendees[0].email).toLowerCase() != settings.identity.email));
     };
     
     // check if the current user is an attendee of this event
     var is_attendee = function(event, role, email)
     {
       var emails = email ? ';'+email.toLowerCase() : settings.identity.emails;
       for (var i=0; event.attendees && i < event.attendees.length; i++) {
         if ((!role || event.attendees[i].role == role) && event.attendees[i].email && emails.indexOf(';'+event.attendees[i].email.toLowerCase()) >= 0)
           return event.attendees[i];
       }
       return false;
     };
     
     // check if the current user is the organizer
     var is_organizer = function(event, email)
     {
       return is_attendee(event, 'ORGANIZER', email) || !event.id;
     };
 
     var load_attachment = function(event, att)
     {
       var qstring = '_id='+urlencode(att.id)+'&_event='+urlencode(event.recurrence_id||event.id)+'&_cal='+urlencode(event.calendar);
 
       // open attachment in frame if it's of a supported mimetype
       if (id && att.mimetype && $.inArray(att.mimetype, settings.mimetypes)>=0) {
         if (rcmail.open_window(rcmail.env.comm_path+'&_action=get-attachment&'+qstring+'&_frame=1', true, true)) {
           return;
         }
       }
 
       rcmail.goto_url('get-attachment', qstring+'&_download=1', false);
     };
 
     // build event attachments list
     var event_show_attachments = function(list, container, event, edit)
     {
       var i, id, len, img, content, li, elem,
         ul = document.createElement('UL');
       ul.className = 'attachmentslist';
 
       for (i=0, len=list.length; i<len; i++) {
         elem = list[i];
         li = document.createElement('LI');
         li.className = elem.classname;
 
         if (edit) {
           rcmail.env.attachments[elem.id] = elem;
           // delete icon
           content = document.createElement('A');
           content.href = '#delete';
           content.title = rcmail.gettext('delete');
           content.className = 'delete';
           $(content).click({id: elem.id}, function(e) { remove_attachment(this, e.data.id); return false; });
 
           if (!rcmail.env.deleteicon)
             content.innerHTML = rcmail.gettext('delete');
           else {
             img = document.createElement('IMG');
             img.src = rcmail.env.deleteicon;
             img.alt = rcmail.gettext('delete');
             content.appendChild(img);
           }
 
           li.appendChild(content);
         }
 
         // name/link
         content = document.createElement('A');
         content.innerHTML = elem.name;
         content.className = 'file';
         content.href = '#load';
         $(content).click({event: event, att: elem}, function(e) {
           load_attachment(e.data.event, e.data.att); return false; });
         li.appendChild(content);
 
         ul.appendChild(li);
       }
 
       if (edit && rcmail.gui_objects.attachmentlist) {
         ul.id = rcmail.gui_objects.attachmentlist.id;
         rcmail.gui_objects.attachmentlist = ul;
       }
 
       container.empty().append(ul);
     };
 
     var remove_attachment = function(elem, id)
     {
       $(elem.parentNode).hide();
       rcmail.env.deleted_attachments.push(id);
       delete rcmail.env.attachments[id];
     };
 
     // event details dialog (show only)
     var event_show_dialog = function(event)
     {
       var $dialog = $("#eventshow").removeClass().addClass('uidialog');
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:false };
       me.selected_event = event;
 
       // allow other plugins to do actions when event form is opened
       rcmail.triggerEvent('calendar-event-init', {o: event});
 
       $dialog.find('div.event-section, div.event-line').hide();
       $('#event-title').html(Q(event.title)).show();
       
       if (event.location)
         $('#event-location').html('@ ' + text2html(event.location)).show();
       if (event.description)
         $('#event-description').show().children('.event-text').html(text2html(event.description, 300, 6));
       if (event.vurl)
         $('#event-url').show().children('.event-text').html(render_link(event.vurl));
       
       // render from-to in a nice human-readable way
       // -> now shown in dialog title
       // $('#event-date').html(Q(me.event_date_text(event))).show();
       
       if (event.recurrence && event.recurrence_text)
         $('#event-repeat').show().children('.event-text').html(Q(event.recurrence_text));
       
       if (event.alarms && event.alarms_text)
         $('#event-alarm').show().children('.event-text').html(Q(event.alarms_text));
       
       if (calendar.name)
         $('#event-calendar').show().children('.event-text').html(Q(calendar.name)).removeClass().addClass('event-text').addClass('cal-'+calendar.id);
       if (event.categories)
         $('#event-category').show().children('.event-text').html(Q(event.categories)).removeClass().addClass('event-text cat-'+String(event.categories).toLowerCase().replace(rcmail.identifier_expr, ''));
       if (event.free_busy)
         $('#event-free-busy').show().children('.event-text').html(Q(rcmail.gettext(event.free_busy, 'calendar')));
       if (event.priority > 0) {
         var priolabels = [ '', rcmail.gettext('highest'), rcmail.gettext('high'), '', '', rcmail.gettext('normal'), '', '', rcmail.gettext('low'), rcmail.gettext('lowest') ];
         $('#event-priority').show().children('.event-text').html(Q(event.priority+' '+priolabels[event.priority]));
       }
 
       if (event.sensitivity && event.sensitivity != 'public') {
         $('#event-sensitivity').show().children('.event-text').html(Q(sensitivitylabels[event.sensitivity]));
         $dialog.addClass('sensitivity-'+event.sensitivity);
       }
 
       // create attachments list
       if ($.isArray(event.attachments)) {
         event_show_attachments(event.attachments, $('#event-attachments').children('.event-text'), event);
         if (event.attachments.length > 0) {
           $('#event-attachments').show();
         }
       }
       else if (calendar.attachments) {
         // fetch attachments, some drivers doesn't set 'attachments' prop of the event?
       }
 
       // list event attendees
       if (calendar.attendees && event.attendees) {
         // sort resources to the end
         event.attendees.sort(function(a,b) {
           var j = a.cutype == 'RESOURCE' ? 1 : 0,
               k = b.cutype == 'RESOURCE' ? 1 : 0;
           return (j - k);
         });
 
         var data, dispname, organizer = false, rsvp = false, line,  morelink, html = '',overflow = '';
         for (var j=0; j < event.attendees.length; j++) {
           data = event.attendees[j];
           dispname = Q(data.name || data.email);
           if (data.email) {
             dispname = '<a href="mailto:' + data.email + '" title="' + Q(data.email) + '" class="mailtolink">' + dispname + '</a>';
             if (data.role == 'ORGANIZER')
               organizer = true;
             else if ((data.status == 'NEEDS-ACTION' || data.status == 'TENTATIVE' || data.rsvp) && settings.identity.emails.indexOf(';'+data.email) >= 0)
               rsvp = data.status.toLowerCase();
           }
           
           line = '<span class="attendee ' + String(data.role == 'ORGANIZER' ? 'organizer' : data.status).toLowerCase() + '">' + dispname + '</span> ';
           if (morelink)
             overflow += line;
           else
             html += line;
           
           // stop listing attendees
           if (j == 7 && event.attendees.length >= 7) {
             morelink = $('<a href="#more" class="morelink"></a>').html(rcmail.gettext('andnmore', 'calendar').replace('$nr', event.attendees.length - j - 1));
           }
         }
         
         if (html && (event.attendees.length > 1 || !organizer)) {
           $('#event-attendees').show()
             .children('.event-text')
             .html(html)
             .find('a.mailtolink').click(function(e) { rcmail.redirect(rcmail.url('mail/compose', { _to:this.href.substr(7) })); return false; });
 
           // display all attendees in a popup when clicking the "more" link
           if (morelink) {
             $('#event-attendees .event-text').append(morelink);
             morelink.click(function(e){
               rcmail.show_popup_dialog(
                 '<div id="all-event-attendees" class="event-attendees">' + html + overflow + '</div>',
                 rcmail.gettext('tabattendees','calendar'),
                 null,
                 { width:450, modal:false });
               $('#all-event-attendees a.mailtolink').click(function(e) { rcmail.redirect(rcmail.url('mail/compose', { _to:this.href.substr(7) })); return false; });
               return false;
             })
           }
         }
         
         $('#event-rsvp')[(rsvp && !is_organizer(event) ? 'show' : 'hide')]();
         $('#event-rsvp .rsvp-buttons input').prop('disabled', false).filter('input[rel='+rsvp+']').prop('disabled', true);
       }
 
       var buttons = {};
       if (calendar.editable && event.editable !== false) {
         buttons[rcmail.gettext('edit', 'calendar')] = function() {
           event_edit_dialog('edit', event);
         };
         buttons[rcmail.gettext('remove', 'calendar')] = function() {
           me.delete_event(event);
           $dialog.dialog('close');
         };
       }
       else {
         buttons[rcmail.gettext('close', 'calendar')] = function(){
           $dialog.dialog('close');
         };
       }
       
       // open jquery UI dialog
       $dialog.dialog({
         modal: false,
         resizable: !bw.ie6,
         closeOnEscape: (!bw.ie6 && !bw.ie7),  // disable for performance reasons
         title: Q(me.event_date_text(event)),
         open: function() {
           $dialog.parent().find('.ui-button').first().focus();
         },
         close: function() {
           $dialog.dialog('destroy').hide();
         },
         buttons: buttons,
         minWidth: 320,
         width: 420
       }).show();
       
       // set dialog size according to content
       me.dialog_resize($dialog.get(0), $dialog.height(), 420);
 /* 
       // add link for "more options" drop-down
       $('<a>')
         .attr('href', '#')
         .html('More Options')
         .addClass('dropdown-link')
         .click(function(){ return false; })
         .insertBefore($dialog.parent().find('.ui-dialog-buttonset').children().first());
 */
     };
 
     // bring up the event dialog (jquery-ui popup)
     var event_edit_dialog = function(action, event)
     {
       // close show dialog first
       $("#eventshow:ui-dialog").dialog('close');
 
       var $dialog = $('<div>');
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:action=='new' };
       me.selected_event = $.extend($.extend({}, event_defaults), event);  // clone event object (with defaults)
       event = me.selected_event; // change reference to clone
       freebusy_ui.needsupdate = false;
 
       // reset dialog first
       $('#eventtabs').get(0).reset();
 
       // allow other plugins to do actions when event form is opened
       rcmail.triggerEvent('calendar-event-init', {o: event});
 
       // event details
       var title = $('#edit-title').val(event.title || '');
       var location = $('#edit-location').val(event.location || '');
       var description = $('#edit-description').html(event.description || '');
       var vurl = $('#edit-url').val(event.vurl || '');
       var categories = $('#edit-categories').val(event.categories);
       var calendars = $('#edit-calendar').val(event.calendar);
       var freebusy = $('#edit-free-busy').val(event.free_busy);
       var priority = $('#edit-priority').val(event.priority);
       var sensitivity = $('#edit-sensitivity').val(event.sensitivity);
       
       var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
       var startdate = $('#edit-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
       var starttime = $('#edit-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
       var enddate = $('#edit-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
       var endtime = $('#edit-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       var allday = $('#edit-allday').get(0);
       var notify = $('#edit-attendees-donotify').get(0);
       var invite = $('#edit-attendees-invite').get(0);
       notify.checked = has_attendees(event), invite.checked = true;
       
       if (event.allDay) {
         starttime.val("12:00").hide();
         endtime.val("13:00").hide();
         allday.checked = true;
       }
       else {
         allday.checked = false;
       }
       
       // set alarm(s)
       // TODO: support multiple alarm entries
       if (event.alarms || action != 'new') {
         if (typeof event.alarms == 'string')
           event.alarms = event.alarms.split(';');
         
         var valarms = event.alarms || [''];
         for (var alarm, i=0; i < valarms.length; i++) {
           alarm = String(valarms[i]).split(':');
           if (!alarm[1] && alarm[0]) alarm[1] = 'DISPLAY';
           $('#eventedit select.edit-alarm-type').val(alarm[1]);
           
           if (alarm[0].match(/@(\d+)/)) {
             var ondate = fromunixtime(parseInt(RegExp.$1));
             $('#eventedit select.edit-alarm-offset').val('@');
             $('#eventedit input.edit-alarm-date').val($.fullCalendar.formatDate(ondate, settings['date_format']));
             $('#eventedit input.edit-alarm-time').val($.fullCalendar.formatDate(ondate, settings['time_format']));
           }
           else if (alarm[0].match(/([-+])(\d+)([MHD])/)) {
             $('#eventedit input.edit-alarm-value').val(RegExp.$2);
             $('#eventedit select.edit-alarm-offset').val(''+RegExp.$1+RegExp.$3);
           }
         }
       }
       // set correct visibility by triggering onchange handlers
       $('#eventedit select.edit-alarm-type, #eventedit select.edit-alarm-offset').change();
       
       // enable/disable alarm property according to backend support
       $('#edit-alarms')[(calendar.alarms ? 'show' : 'hide')]();
 
       // check categories drop-down: add value if not exists
       if (event.categories && !categories.find("option[value='"+event.categories+"']").length) {
         $('<option>').attr('value', event.categories).text(event.categories).appendTo(categories).prop('selected', true);
       }
 
       // set recurrence form
       var recurrence, interval, rrtimes, rrenddate;
       var load_recurrence_tab = function()
       {
         recurrence = $('#edit-recurrence-frequency').val(event.recurrence ? event.recurrence.FREQ : '').change();
         interval = $('#eventedit select.edit-recurrence-interval').val(event.recurrence ? event.recurrence.INTERVAL : 1);
         rrtimes = $('#edit-recurrence-repeat-times').val(event.recurrence ? event.recurrence.COUNT : 1);
         rrenddate = $('#edit-recurrence-enddate').val(event.recurrence && event.recurrence.UNTIL ? $.fullCalendar.formatDate(parseISO8601(event.recurrence.UNTIL), settings['date_format']) : '');
         $('#eventedit input.edit-recurrence-until:checked').prop('checked', false);
       
         var weekdays = ['SU','MO','TU','WE','TH','FR','SA'];
         var rrepeat_id = '#edit-recurrence-repeat-forever';
         if (event.recurrence && event.recurrence.COUNT)      rrepeat_id = '#edit-recurrence-repeat-count';
         else if (event.recurrence && event.recurrence.UNTIL) rrepeat_id = '#edit-recurrence-repeat-until';
         $(rrepeat_id).prop('checked', true);
       
         if (event.recurrence && event.recurrence.BYDAY && event.recurrence.FREQ == 'WEEKLY') {
           var wdays = event.recurrence.BYDAY.split(',');
           $('input.edit-recurrence-weekly-byday').val(wdays);
         }
         if (event.recurrence && event.recurrence.BYMONTHDAY) {
           $('input.edit-recurrence-monthly-bymonthday').val(String(event.recurrence.BYMONTHDAY).split(','));
           $('input.edit-recurrence-monthly-mode').val(['BYMONTHDAY']);
         }
         if (event.recurrence && event.recurrence.BYDAY && (event.recurrence.FREQ == 'MONTHLY' || event.recurrence.FREQ == 'YEARLY')) {
           var byday, section = event.recurrence.FREQ.toLowerCase();
           if ((byday = String(event.recurrence.BYDAY).match(/(-?[1-4])([A-Z]+)/))) {
             $('#edit-recurrence-'+section+'-prefix').val(byday[1]);
             $('#edit-recurrence-'+section+'-byday').val(byday[2]);
           }
           $('input.edit-recurrence-'+section+'-mode').val(['BYDAY']);
         }
         else if (event.start) {
           $('#edit-recurrence-monthly-byday').val(weekdays[event.start.getDay()]);
         }
         if (event.recurrence && event.recurrence.BYMONTH) {
           $('input.edit-recurrence-yearly-bymonth').val(String(event.recurrence.BYMONTH).split(','));
         }
         else if (event.start) {
           $('input.edit-recurrence-yearly-bymonth').val([String(event.start.getMonth()+1)]);
         }
       };
       
       // show warning if editing a recurring event
       if (event.id && event.recurrence) {
         var sel = event.thisandfuture ? 'future' : (event.isexception ? 'current' : 'all');
         $('#edit-recurring-warning').show();
         $('input.edit-recurring-savemode[value="'+sel+'"]').prop('checked', true);
       }
       else
         $('#edit-recurring-warning').hide();
 
       // init attendees tab
       var organizer = !event.attendees || is_organizer(event),
         allow_invitations = organizer || (calendar.owner && calendar.owner == 'anonymous') || settings.invite_shared;
       event_attendees = [];
       attendees_list = $('#edit-attendees-table > tbody').html('');
       resources_list = $('#edit-resources-table > tbody').html('');
       $('#edit-attendees-notify')[(notify.checked && allow_invitations ? 'show' : 'hide')]();
       $('#edit-localchanges-warning')[(has_attendees(event) && !(allow_invitations || (calendar.owner && is_organizer(event, calendar.owner))) ? 'show' : 'hide')]();
 
       var load_attendees_tab = function()
       {
         if (event.attendees) {
           for (var j=0; j < event.attendees.length; j++)
             add_attendee(event.attendees[j], !allow_invitations);
         }
 
         // select the correct organizer identity
         var identity_id = 0;
         $.each(settings.identities, function(i,v){
           if (organizer && v == organizer.email) {
             identity_id = i;
             return false;
           }
         });
         $('#edit-identities-list').val(identity_id);
         $('#edit-attendees-form')[(allow_invitations?'show':'hide')]();
         $('#edit-attendee-schedule')[(calendar.freebusy?'show':'hide')]();
       };
 
       // attachments
       var load_attachments_tab = function()
       {
         rcmail.enable_command('remove-attachment', !calendar.readonly);
         rcmail.env.deleted_attachments = [];
         // we're sharing some code for uploads handling with app.js
         rcmail.env.attachments = [];
         rcmail.env.compose_id = event.id; // for rcmail.async_upload_form()
 
         if ($.isArray(event.attachments)) {
           event_show_attachments(event.attachments, $('#edit-attachments'), event, true);
         }
         else {
           $('#edit-attachments > ul').empty();
           // fetch attachments, some drivers doesn't set 'attachments' array for event?
         }
       };
       
       // init dialog buttons
       var buttons = {};
       
       // save action
       buttons[rcmail.gettext('save', 'calendar')] = function() {
         var start = parse_datetime(allday.checked ? '12:00' : starttime.val(), startdate.val());
         var end   = parse_datetime(allday.checked ? '13:00' : endtime.val(), enddate.val());
         
         // basic input validatetion
         if (start.getTime() > end.getTime()) {
           alert(rcmail.gettext('invalideventdates', 'calendar'));
           return false;
         }
         
         // post data to server
         var data = {
           calendar: event.calendar,
           start: date2servertime(start),
           end: date2servertime(end),
           allday: allday.checked?1:0,
           title: title.val(),
           description: description.val(),
           location: location.val(),
           categories: categories.val(),
           vurl: vurl.val(),
           free_busy: freebusy.val(),
           priority: priority.val(),
           sensitivity: sensitivity.val(),
           recurrence: '',
           alarms: '',
           attendees: event_attendees,
           deleted_attachments: rcmail.env.deleted_attachments,
           attachments: []
         };
 
         // serialize alarm settings
         // TODO: support multiple alarm entries
         var alarm = $('#eventedit select.edit-alarm-type').val();
         if (alarm) {
           var val, offset = $('#eventedit select.edit-alarm-offset').val();
           if (offset == '@')
             data.alarms = '@' + date2unixtime(parse_datetime($('#eventedit input.edit-alarm-time').val(), $('#eventedit input.edit-alarm-date').val())) + ':' + alarm;
           else if ((val = parseInt($('#eventedit input.edit-alarm-value').val())) && !isNaN(val) && val >= 0)
             data.alarms = offset[0] + val + offset[1] + ':' + alarm;
         }
 
         // uploaded attachments list
         for (var i in rcmail.env.attachments)
           if (i.match(/^rcmfile(.+)/))
             data.attachments.push(RegExp.$1);
 
         // read attendee roles
         $('select.edit-attendee-role').each(function(i, elem){
           if (data.attendees[i])
             data.attendees[i].role = $(elem).val();
         });
         
         if (organizer)
           data._identity = $('#edit-identities-list option:selected').val();
         
         // don't submit attendees if only myself is added as organizer
         if (data.attendees.length == 1 && data.attendees[0].role == 'ORGANIZER' && String(data.attendees[0].email).toLowerCase() == settings.identity.email)
           data.attendees = [];
         
         // tell server to send notifications
         if ((data.attendees.length || (event.id && event.attendees.length)) && allow_invitations && (notify.checked || invite.checked)) {
           data._notify = 1;
         }
 
         // gather recurrence settings
         var freq;
         if ((freq = recurrence.val()) != '') {
           data.recurrence = {
             FREQ: freq,
             INTERVAL: $('#edit-recurrence-interval-'+freq.toLowerCase()).val()
           };
           
           var until = $('input.edit-recurrence-until:checked').val();
           if (until == 'count')
             data.recurrence.COUNT = rrtimes.val();
           else if (until == 'until')
             data.recurrence.UNTIL = date2servertime(parse_datetime(endtime.val(), rrenddate.val()));
           
           if (freq == 'WEEKLY') {
             var byday = [];
             $('input.edit-recurrence-weekly-byday:checked').each(function(){ byday.push(this.value); });
             if (byday.length)
               data.recurrence.BYDAY = byday.join(',');
           }
           else if (freq == 'MONTHLY') {
             var mode = $('input.edit-recurrence-monthly-mode:checked').val(), bymonday = [];
             if (mode == 'BYMONTHDAY') {
               $('input.edit-recurrence-monthly-bymonthday:checked').each(function(){ bymonday.push(this.value); });
               if (bymonday.length)
                 data.recurrence.BYMONTHDAY = bymonday.join(',');
             }
             else
               data.recurrence.BYDAY = $('#edit-recurrence-monthly-prefix').val() + $('#edit-recurrence-monthly-byday').val();
           }
           else if (freq == 'YEARLY') {
             var byday, bymonth = [];
             $('input.edit-recurrence-yearly-bymonth:checked').each(function(){ bymonth.push(this.value); });
             if (bymonth.length)
               data.recurrence.BYMONTH = bymonth.join(',');
             if ((byday = $('#edit-recurrence-yearly-byday').val()))
               data.recurrence.BYDAY = $('#edit-recurrence-yearly-prefix').val() + byday;
           }
         }
 
         data.calendar = calendars.val();
 
         if (event.id) {
           data.id = event.id;
           if (event.recurrence)
             data._savemode = $('input.edit-recurring-savemode:checked').val();
           if (data.calendar && data.calendar != event.calendar)
             data._fromcalendar = event.calendar;
         }
 
         update_event(action, data);
         $dialog.dialog("close");
       };
 
       if (event.id) {
         buttons[rcmail.gettext('remove', 'calendar')] = function() {
           me.delete_event(event);
           $dialog.dialog('close');
         };
       }
 
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
 
       // show/hide tabs according to calendar's feature support
       $('#edit-tab-attendees')[(calendar.attendees?'show':'hide')]();
       $('#edit-tab-resources')[(calendar.resources?'show':'hide')]();
       $('#edit-tab-attachments')[(calendar.attachments?'show':'hide')]();
 
       // activate the first tab
       $('#eventtabs').tabs('select', 0);
       
       // hack: set task to 'calendar' to make all dialog actions work correctly
       var comm_path_before = rcmail.env.comm_path;
       rcmail.env.comm_path = comm_path_before.replace(/_task=[a-z]+/, '_task=calendar');
 
       var editform = $("#eventedit");
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: (!bw.ie6 && !bw.ie7),  // disable for performance reasons
         closeOnEscape: false,
         title: rcmail.gettext((action == 'edit' ? 'edit_event' : 'new_event'), 'calendar'),
         open: function() {
           $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().addClass('mainaction');
         },
         close: function() {
           editform.hide().appendTo(document.body);
           $dialog.dialog("destroy").remove();
           rcmail.ksearch_blur();
           rcmail.ksearch_destroy();
           freebusy_data = {};
           rcmail.env.comm_path = comm_path_before;  // restore comm_path
         },
         buttons: buttons,
         minWidth: 500,
         width: 580
       }).append(editform.show());  // adding form content AFTERWARDS massively speeds up opening on IE6
 
       // set dialog size according to form content
       me.dialog_resize($dialog.get(0), editform.height() + (bw.ie ? 20 : 0), 530);
 
       title.select();
 
       // init other tabs asynchronously
       window.setTimeout(load_recurrence_tab, exec_deferred);
       if (calendar.attendees)
         window.setTimeout(load_attendees_tab, exec_deferred);
       if (calendar.attachments)
         window.setTimeout(load_attachments_tab, exec_deferred);
     };
 
     // open a dialog to display detailed free-busy information and to find free slots
     var event_freebusy_dialog = function()
     {
       var $dialog = $('#eventfreebusy'),
         event = me.selected_event;
       
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
       
       if (!event_attendees.length)
         return false;
       
       // set form elements
       var allday = $('#edit-allday').get(0);
       var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
       freebusy_ui.startdate = $('#schedule-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
       freebusy_ui.starttime = $('#schedule-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
       freebusy_ui.enddate = $('#schedule-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
       freebusy_ui.endtime = $('#schedule-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       
       if (allday.checked) {
         freebusy_ui.starttime.val("12:00").hide();
         freebusy_ui.endtime.val("13:00").hide();
         event.allDay = true;
       }
       
       // read attendee roles from drop-downs
       $('select.edit-attendee-role').each(function(i, elem){
         if (event_attendees[i])
           event_attendees[i].role = $(elem).val();
       });
       
       // render time slots
       var now = new Date(), fb_start = new Date(), fb_end = new Date();
       fb_start.setTime(event.start);
       fb_start.setHours(0); fb_start.setMinutes(0); fb_start.setSeconds(0); fb_start.setMilliseconds(0);
       fb_end.setTime(fb_start.getTime() + DAY_MS);
       
       freebusy_data = { required:{}, all:{} };
       freebusy_ui.loading = 1;  // prevent render_freebusy_grid() to load data yet
       freebusy_ui.numdays = Math.max(allday.checked ? 14 : 1, Math.ceil(duration * 2 / 86400));
       freebusy_ui.interval = allday.checked ? 1440 : 60;
       freebusy_ui.start = fb_start;
       freebusy_ui.end = new Date(freebusy_ui.start.getTime() + DAY_MS * freebusy_ui.numdays);
       render_freebusy_grid(0);
       
       // render list of attendees
       freebusy_ui.attendees = {};
       var domid, dispname, data, role_html, list_html = '';
       for (var i=0; i < event_attendees.length; i++) {
         data = event_attendees[i];
         dispname = Q(data.name || data.email);
         domid = String(data.email).replace(rcmail.identifier_expr, '');
         role_html = '<a class="attendee-role-toggle" id="rcmlia' + domid + '" title="' + Q(rcmail.gettext('togglerole', 'calendar')) + '">&nbsp;</a>';
         list_html += '<div class="attendee ' + String(data.role).toLowerCase() + '" id="rcmli' + domid + '">' + role_html + dispname + '</div>';
         
         // clone attendees data for local modifications
         freebusy_ui.attendees[i] = freebusy_ui.attendees[domid] = $.extend({}, data);
       }
       
       // add total row
       list_html += '<div class="attendee spacer">&nbsp;</div>';
       list_html += '<div class="attendee total">' + rcmail.gettext('reqallattendees','calendar') + '</div>';
       
       $('#schedule-attendees-list').html(list_html)
         .unbind('click.roleicons')
         .bind('click.roleicons', function(e){
           // toggle attendee status upon click on icon
           if (e.target.id && e.target.id.match(/rcmlia(.+)/)) {
             var attendee, domid = RegExp.$1,
                 roles = [ 'REQ-PARTICIPANT', 'OPT-PARTICIPANT', 'NON-PARTICIPANT', 'CHAIR' ];
             if ((attendee = freebusy_ui.attendees[domid]) && attendee.role != 'ORGANIZER') {
               var req = attendee.role != 'OPT-PARTICIPANT' && attendee.role != 'NON-PARTICIPANT';
               var j = $.inArray(attendee.role, roles);
               j = (j+1) % roles.length;
               attendee.role = roles[j];
               $(e.target).parent().removeClass().addClass('attendee '+String(attendee.role).toLowerCase());
               
               // update total display if required-status changed
               if (req != (roles[j] != 'OPT-PARTICIPANT' && roles[j] != 'NON-PARTICIPANT')) {
                 compute_freebusy_totals();
                 update_freebusy_display(attendee.email);
               }
             }
           }
           
           return false;
         });
       
       // enable/disable buttons
       $('#shedule-find-prev').button('option', 'disabled', (fb_start.getTime() < now.getTime()));
       
       // dialog buttons
       var buttons = {};
       
       buttons[rcmail.gettext('select', 'calendar')] = function() {
         $('#edit-startdate').val(freebusy_ui.startdate.val());
         $('#edit-starttime').val(freebusy_ui.starttime.val());
         $('#edit-enddate').val(freebusy_ui.enddate.val());
         $('#edit-endtime').val(freebusy_ui.endtime.val());
         
         // write role changes back to main dialog
         $('select.edit-attendee-role').each(function(i, elem){
           if (event_attendees[i] && freebusy_ui.attendees[i]) {
             event_attendees[i].role = freebusy_ui.attendees[i].role;
             $(elem).val(event_attendees[i].role);
           }
         });
         
         if (freebusy_ui.needsupdate)
           update_freebusy_status(me.selected_event);
         freebusy_ui.needsupdate = false;
         $dialog.dialog("close");
       };
       
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
       
       $dialog.dialog({
         modal: true,
         resizable: true,
         closeOnEscape: (!bw.ie6 && !bw.ie7),
         title: rcmail.gettext('scheduletime', 'calendar'),
         open: function() {
           $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().focus();
         },
         close: function() {
           if (bw.ie6)
             $("#edit-attendees-table").css('visibility','visible');
           $dialog.dialog("destroy").hide();
         },
         resizeStop: function() {
           render_freebusy_overlay();
         },
         buttons: buttons,
         minWidth: 640,
         width: 850
       }).show();
       
       // hide edit dialog on IE6 because of drop-down elements
       if (bw.ie6)
         $("#edit-attendees-table").css('visibility','hidden');
       
       // adjust dialog size to fit grid without scrolling
       var gridw = $('#schedule-freebusy-times').width();
       var overflow = gridw - $('#attendees-freebusy-table td.times').width() + 1;
       me.dialog_resize($dialog.get(0), $dialog.height() + (bw.ie ? 20 : 0), 800 + Math.max(0, overflow));
       
       // fetch data from server
       freebusy_ui.loading = 0;
       load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
     };
 
     // render an HTML table showing free-busy status for all the event attendees
     var render_freebusy_grid = function(delta)
     {
       if (delta) {
         freebusy_ui.start.setTime(freebusy_ui.start.getTime() + DAY_MS * delta);
         fix_date(freebusy_ui.start);
         
         // skip weekends if in workinhoursonly-mode
         if (Math.abs(delta) == 1 && freebusy_ui.workinhoursonly) {
           while (is_weekend(freebusy_ui.start))
             freebusy_ui.start.setTime(freebusy_ui.start.getTime() + DAY_MS * delta);
           fix_date(freebusy_ui.start);
         }
         
         freebusy_ui.end = new Date(freebusy_ui.start.getTime() + DAY_MS * freebusy_ui.numdays);
       }
       
       var dayslots = Math.floor(1440 / freebusy_ui.interval);
       var date_format = 'ddd '+ (dayslots <= 2 ? settings.date_short : settings.date_format);
       var lastdate, datestr, css,
         curdate = new Date(),
         allday = (freebusy_ui.interval == 1440),
         times_css = (allday ? 'allday ' : ''),
         dates_row = '<tr class="dates">',
         times_row = '<tr class="times">',
         slots_row = '';
       for (var s = 0, t = freebusy_ui.start.getTime(); t < freebusy_ui.end.getTime(); s++) {
         curdate.setTime(t);
         datestr = fc.fullCalendar('formatDate', curdate, date_format);
         if (datestr != lastdate) {
           if (lastdate && !allday) break;
           dates_row += '<th colspan="' + dayslots + '" class="boxtitle date' + $.fullCalendar.formatDate(curdate, 'ddMMyyyy') + '">' + Q(datestr) + '</th>';
           lastdate = datestr;
         }
         
         // set css class according to working hours
         css = is_weekend(curdate) || (freebusy_ui.interval <= 60 && !is_workinghour(curdate)) ? 'offhours' : 'workinghours';
         times_row += '<td class="' + times_css + css + '" id="t-' + Math.floor(t/1000) + '">' + Q(allday ? rcmail.gettext('all-day','calendar') : $.fullCalendar.formatDate(curdate, settings['time_format'])) + '</td>';
         slots_row += '<td class="' + css + ' unknown">&nbsp;</td>';
         
         t += freebusy_ui.interval * 60000;
       }
       dates_row += '</tr>';
       times_row += '</tr>';
       
       // render list of attendees
       var domid, data, list_html = '', times_html = '';
       for (var i=0; i < event_attendees.length; i++) {
         data = event_attendees[i];
         domid = String(data.email).replace(rcmail.identifier_expr, '');
         times_html += '<tr id="fbrow' + domid + '">' + slots_row + '</tr>';
       }
       
       // add line for all/required attendees
       times_html += '<tr class="spacer"><td colspan="' + (dayslots * freebusy_ui.numdays) + '">&nbsp;</td>';
       times_html += '<tr id="fbrowall">' + slots_row + '</tr>';
       
       var table = $('#schedule-freebusy-times');
       table.children('thead').html(dates_row + times_row);
       table.children('tbody').html(times_html);
       
       // initialize event handlers on grid
       if (!freebusy_ui.grid_events) {
         freebusy_ui.grid_events = true;
         table.children('thead').click(function(e){
           // move event to the clicked date/time
           if (e.target.id && e.target.id.match(/t-(\d+)/)) {
             var newstart = new Date(RegExp.$1 * 1000);
             // set time to 00:00
             if (me.selected_event.allDay) {
               newstart.setMinutes(0);
               newstart.setHours(0);
             }
             update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
             render_freebusy_overlay();
           }
         })
       }
       
       // if we have loaded free-busy data, show it
       if (!freebusy_ui.loading) {
         if (freebusy_ui.start < freebusy_data.start || freebusy_ui.end > freebusy_data.end || freebusy_ui.interval != freebusy_data.interval) {
           load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
         }
         else {
           for (var email, i=0; i < event_attendees.length; i++) {
             if ((email = event_attendees[i].email))
               update_freebusy_display(email);
           }
         }
       }
       
       // render current event date/time selection over grid table
       // use timeout to let the dom attributes (width/height/offset) be set first
       window.setTimeout(function(){ render_freebusy_overlay(); }, 10);
     };
     
     // render overlay element over the grid to visiualize the current event date/time
     var render_freebusy_overlay = function()
     {
       var overlay = $('#schedule-event-time');
       if (me.selected_event.end.getTime() <= freebusy_ui.start.getTime() || me.selected_event.start.getTime() >= freebusy_ui.end.getTime()) {
         overlay.hide();
         if (overlay.data('isdraggable'))
           overlay.draggable('disable');
       }
       else {
         var table = $('#schedule-freebusy-times'),
           width = 0,
           pos = { top:table.children('thead').height(), left:0 },
           eventstart = date2unixtime(clone_date(me.selected_event.start, me.selected_event.allDay?1:0)),
           eventend = date2unixtime(clone_date(me.selected_event.end, me.selected_event.allDay?2:0)) - 60,
           slotstart = date2unixtime(freebusy_ui.start),
           slotsize = freebusy_ui.interval * 60,
           slotend, fraction, $cell;
         
         // iterate through slots to determine position and size of the overlay
         table.children('thead').find('td').each(function(i, cell){
           slotend = slotstart + slotsize - 1;
           // event starts in this slot: compute left
           if (eventstart >= slotstart && eventstart <= slotend) {
             fraction = 1 - (slotend - eventstart) / slotsize;
             pos.left = Math.round(cell.offsetLeft + cell.offsetWidth * fraction);
           }
           // event ends in this slot: compute width
           if (eventend >= slotstart && eventend <= slotend) {
             fraction = 1 - (slotend - eventend) / slotsize;
             width = Math.round(cell.offsetLeft + cell.offsetWidth * fraction) - pos.left;
           }
 
           slotstart = slotstart + slotsize;
         });
 
         if (!width)
           width = table.width() - pos.left;
 
         // overlay is visible
         if (width > 0) {
           overlay.css({ width: (width-5)+'px', height:(table.children('tbody').height() - 4)+'px', left:pos.left+'px', top:pos.top+'px' }).show();
           
           // configure draggable
           if (!overlay.data('isdraggable')) {
             overlay.draggable({
               axis: 'x',
               scroll: true,
               stop: function(e, ui){
                 // convert pixels to time
                 var px = ui.position.left;
                 var range_p = $('#schedule-freebusy-times').width();
                 var range_t = freebusy_ui.end.getTime() - freebusy_ui.start.getTime();
                 var newstart = new Date(freebusy_ui.start.getTime() + px * (range_t / range_p));
                 newstart.setSeconds(0); newstart.setMilliseconds(0);
                 // snap to day boundaries
                 if (me.selected_event.allDay) {
                   if (newstart.getHours() >= 12)  // snap to next day
                     newstart.setTime(newstart.getTime() + DAY_MS);
                   newstart.setMinutes(0);
                   newstart.setHours(0);
                 }
                 else {
                   // round to 5 minutes
                   var round = newstart.getMinutes() % 5;
                   if (round > 2.5) newstart.setTime(newstart.getTime() + (5 - round) * 60000);
                   else if (round > 0) newstart.setTime(newstart.getTime() - round * 60000);
                 }
                 // update event times and display
                 update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
                 if (me.selected_event.allDay)
                   render_freebusy_overlay();
               }
             }).data('isdraggable', true);
           }
           else
             overlay.draggable('enable');
         }
         else
           overlay.draggable('disable').hide();
       }
       
     };
     
     
     // fetch free-busy information for each attendee from server
     var load_freebusy_data = function(from, interval)
     {
       var start = new Date(from.getTime() - DAY_MS * 2);  // start 2 days before event
       fix_date(start);
       var end = new Date(start.getTime() + DAY_MS * Math.max(14, freebusy_ui.numdays + 7));   // load min. 14 days
       freebusy_ui.numrequired = 0;
       freebusy_data.all = [];
       freebusy_data.required = [];
 
       // load free-busy information for every attendee
       var domid, email;
       for (var i=0; i < event_attendees.length; i++) {
         if ((email = event_attendees[i].email)) {
           domid = String(email).replace(rcmail.identifier_expr, '');
           $('#rcmli' + domid).addClass('loading');
           freebusy_ui.loading++;
           
           $.ajax({
             type: 'GET',
             dataType: 'json',
             url: rcmail.url('freebusy-times'),
             data: { email:email, start:date2servertime(clone_date(start, 1)), end:date2servertime(clone_date(end, 2)), interval:interval, _remote:1 },
             success: function(data) {
               freebusy_ui.loading--;
               
               // find attendee 
               var attendee = null;
               for (var i=0; i < event_attendees.length; i++) {
                 if (freebusy_ui.attendees[i].email == data.email) {
                   attendee = freebusy_ui.attendees[i];
                   break;
                 }
               }
               
               // copy data to member var
               var ts, req = attendee.role != 'OPT-PARTICIPANT';
               freebusy_data.start = parseISO8601(data.start);
               freebusy_data[data.email] = {};
               for (var i=0; i < data.slots.length; i++) {
                 ts = data.times[i] + '';
                 freebusy_data[data.email][ts] = data.slots[i];
                 
                 // set totals
                 if (!freebusy_data.required[ts])
                   freebusy_data.required[ts] = [0,0,0,0];
                 if (req)
                   freebusy_data.required[ts][data.slots[i]]++;
                 
                 if (!freebusy_data.all[ts])
                   freebusy_data.all[ts] = [0,0,0,0];
                 freebusy_data.all[ts][data.slots[i]]++;
               }
               freebusy_data.end = parseISO8601(data.end);
               freebusy_data.interval = data.interval;
 
               // hide loading indicator
               var domid = String(data.email).replace(rcmail.identifier_expr, '');
               $('#rcmli' + domid).removeClass('loading');
               
               // update display
               update_freebusy_display(data.email);
             }
           });
           
           // count required attendees
           if (freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT')
             freebusy_ui.numrequired++;
         }
       }
     };
     
     // re-calculate total status after role change
     var compute_freebusy_totals = function()
     {
       freebusy_ui.numrequired = 0;
       freebusy_data.all = [];
       freebusy_data.required = [];
       
       var email, req, status;
       for (var i=0; i < event_attendees.length; i++) {
         if (!(email = event_attendees[i].email))
           continue;
         
         req = freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT';
         if (req)
           freebusy_ui.numrequired++;
         
         for (var ts in freebusy_data[email]) {
           if (!freebusy_data.required[ts])
             freebusy_data.required[ts] = [0,0,0,0];
           if (!freebusy_data.all[ts])
             freebusy_data.all[ts] = [0,0,0,0];
           
           status = freebusy_data[email][ts];
           freebusy_data.all[ts][status]++;
           
           if (req)
             freebusy_data.required[ts][status]++;
         }
       }
     };
 
     // update free-busy grid with status loaded from server
     var update_freebusy_display = function(email)
     {
       var status_classes = ['unknown','free','busy','tentative','out-of-office'];
       var domid = String(email).replace(rcmail.identifier_expr, '');
       var row = $('#fbrow' + domid);
       var rowall = $('#fbrowall').children();
       var dateonly = freebusy_ui.interval > 60,
         t, ts = date2timestring(freebusy_ui.start, dateonly),
         curdate = new Date(),
         fbdata = freebusy_data[email];
 
       if (fbdata && fbdata[ts] !== undefined && row.length) {
         t = freebusy_ui.start.getTime();
         row.children().each(function(i, cell){
           curdate.setTime(t);
           ts = date2timestring(curdate, dateonly);
           cell.className = cell.className.replace('unknown', fbdata[ts] ? status_classes[fbdata[ts]] : 'unknown');
 
           // also update total row if all data was loaded
           if (freebusy_ui.loading == 0 && freebusy_data.all[ts] && (cell = rowall.get(i))) {
             var workinghours = cell.className.indexOf('workinghours') >= 0;
             var all_status = freebusy_data.all[ts][2] ? 'busy' : 'unknown';
               req_status = freebusy_data.required[ts][2] ? 'busy' : 'free';
             for (var j=1; j < status_classes.length; j++) {
               if (freebusy_ui.numrequired && freebusy_data.required[ts][j] >= freebusy_ui.numrequired)
                 req_status = status_classes[j];
               if (freebusy_data.all[ts][j] == event_attendees.length)
                 all_status = status_classes[j];
             }
             
             cell.className = (workinghours ? 'workinghours ' : 'offhours ') + req_status +  ' all-' + all_status;
           }
           
           t += freebusy_ui.interval * 60000;
         });
       }
     };
     
     // write changed event date/times back to form fields
     var update_freebusy_dates = function(start, end)
     {
       // fix all-day evebt times
       if (me.selected_event.allDay) {
         var numdays = Math.floor((me.selected_event.end.getTime() - me.selected_event.start.getTime()) / DAY_MS);
         start.setHours(12);
         start.setMinutes(0);
         end.setTime(start.getTime() + numdays * DAY_MS);
         end.setHours(13);
         end.setMinutes(0);
       }
       me.selected_event.start = start;
       me.selected_event.end = end;
       freebusy_ui.startdate.val($.fullCalendar.formatDate(start, settings['date_format']));
       freebusy_ui.starttime.val($.fullCalendar.formatDate(start, settings['time_format']));
       freebusy_ui.enddate.val($.fullCalendar.formatDate(end, settings['date_format']));
       freebusy_ui.endtime.val($.fullCalendar.formatDate(end, settings['time_format']));
       freebusy_ui.needsupdate = true;
     };
 
     // attempt to find a time slot where all attemdees are available
     var freebusy_find_slot = function(dir)
     {
       // exit if free-busy data isn't available yet
       if (!freebusy_data || !freebusy_data.start)
         return false;
 
       var event = me.selected_event,
         eventstart = clone_date(event.start, event.allDay ? 1 : 0).getTime(),  // calculate with integers
         eventend = clone_date(event.end, event.allDay ? 2 : 0).getTime(),
         duration = eventend - eventstart - (event.allDay ? HOUR_MS : 0),  // make sure we don't cross day borders on DST change
         sinterval = freebusy_data.interval * 60000,
         intvlslots = 1,
         numslots = Math.ceil(duration / sinterval),
         checkdate, slotend, email, ts, slot, slotdate = new Date();
 
       // shift event times to next possible slot
       eventstart += sinterval * intvlslots * dir;
       eventend += sinterval * intvlslots * dir;
 
       // iterate through free-busy slots and find candidates
       var candidatecount = 0, candidatestart = candidateend = success = false;
       for (slot = dir > 0 ? freebusy_data.start.getTime() : freebusy_data.end.getTime() - sinterval;
             (dir > 0 && slot < freebusy_data.end.getTime()) || (dir < 0 && slot >= freebusy_data.start.getTime());
             slot += sinterval * dir) {
         slotdate.setTime(slot);
         // fix slot if just crossed a DST change
         if (event.allDay) {
           fix_date(slotdate);
           slot = slotdate.getTime();
         }
         slotend = slot + sinterval;
 
         if ((dir > 0 && slotend <= eventstart) || (dir < 0 && slot >= eventend))  // skip
           continue;
 
         // respect workingours setting
         if (freebusy_ui.workinhoursonly) {
           if (is_weekend(slotdate) || (freebusy_data.interval <= 60 && !is_workinghour(slotdate))) {  // skip off-hours
             candidatestart = candidateend = false;
             candidatecount = 0;
             continue;
           }
         }
 
         if (!candidatestart)
           candidatestart = slot;
 
         // check freebusy data for all attendees
         ts = date2timestring(slotdate, freebusy_data.interval > 60);
         for (var i=0; i < event_attendees.length; i++) {
           if (freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT' && (email = freebusy_ui.attendees[i].email) && freebusy_data[email] && freebusy_data[email][ts] > 1) {
             candidatestart = candidateend = false;
             break;
           }
         }
         
         // occupied slot
         if (!candidatestart) {
           slot += Math.max(0, intvlslots - candidatecount - 1) * sinterval * dir;
           candidatecount = 0;
           continue;
         }
         
         // set candidate end to slot end time
         candidatecount++;
         if (dir < 0 && !candidateend)
           candidateend = slotend;
         
         // if candidate is big enough, this is it!
         if (candidatecount == numslots) {
           if (dir > 0) {
             event.start.setTime(candidatestart);
             event.end.setTime(candidatestart + duration);
           }
           else {
             event.end.setTime(candidateend);
             event.start.setTime(candidateend - duration);
           }
           success = true;
           break;
         }
       }
       
       // update event date/time display
       if (success) {
         update_freebusy_dates(event.start, event.end);
         
         // move freebusy grid if necessary
         var offset = Math.ceil((event.start.getTime() - freebusy_ui.end.getTime()) / DAY_MS);
         if (event.start.getTime() >= freebusy_ui.end.getTime())
           render_freebusy_grid(Math.max(1, offset));
         else if (event.end.getTime() <= freebusy_ui.start.getTime())
           render_freebusy_grid(Math.min(-1, offset));
         else
           render_freebusy_overlay();
         
         var now = new Date();
         $('#shedule-find-prev').button('option', 'disabled', (event.start.getTime() < now.getTime()));
       }
       else {
         alert(rcmail.gettext('noslotfound','calendar'));
       }
     };
 
 
     // update event properties and attendees availability if event times have changed
     var event_times_changed = function()
     {
       if (me.selected_event) {
         var allday = $('#edit-allday').get(0);
         me.selected_event.allDay = allday.checked;
         me.selected_event.start = parse_datetime(allday.checked ? '12:00' : $('#edit-starttime').val(), $('#edit-startdate').val());
         me.selected_event.end   = parse_datetime(allday.checked ? '13:00' : $('#edit-endtime').val(), $('#edit-enddate').val());
         if (event_attendees)
           freebusy_ui.needsupdate = true;
         $('#edit-startdate').data('duration', Math.round((me.selected_event.end.getTime() - me.selected_event.start.getTime()) / 1000));
       }
     };
 
 
     // add the given list of participants
     var add_attendees = function(names, params)
     {
       names = explode_quoted_string(names.replace(/,\s*$/, ''), ',');
 
       // parse name/email pairs
       var item, email, name, success = false;
       for (var i=0; i < names.length; i++) {
         email = name = '';
         item = $.trim(names[i]);
         
         if (!item.length) {
           continue;
         } // address in brackets without name (do nothing)
         else if (item.match(/^<[^@]+@[^>]+>$/)) {
           email = item.replace(/[<>]/g, '');
         } // address without brackets and without name (add brackets)
         else if (rcube_check_email(item)) {
           email = item;
         } // address with name
         else if (item.match(/([^\s<@]+@[^>]+)>*$/)) {
           email = RegExp.$1;
           name = item.replace(email, '').replace(/^["\s<>]+/, '').replace(/["\s<>]+$/, '');
         }
         if (email) {
           add_attendee($.extend({ email:email, name:name }, params));
           success = true;
         }
         else {
           alert(rcmail.gettext('noemailwarning'));
         }
       }
       
       return success;
     };
 
     // add the given attendee to the list
     var add_attendee = function(data, readonly)
     {
       if (!me.selected_event)
         return false;
 
       // check for dupes...
       var exists = false;
       $.each(event_attendees, function(i, v){ exists |= (v.email == data.email); });
       if (exists)
         return false;
       
       var calendar = me.selected_event && me.calendars[me.selected_event.calendar] ? me.calendars[me.selected_event.calendar] : me.calendars[me.selected_calendar];
 
       var dispname = Q(data.name || data.email);
       if (data.email)
         dispname = '<a href="mailto:' + data.email + '" title="' + Q(data.email) + '" class="mailtolink">' + dispname + '</a>';
       
       // role selection
       var organizer = data.role == 'ORGANIZER';
       var opts = {};
       if (organizer)
         opts.ORGANIZER = rcmail.gettext('calendar.roleorganizer');
       opts['REQ-PARTICIPANT'] = rcmail.gettext('calendar.rolerequired');
       opts['OPT-PARTICIPANT'] = rcmail.gettext('calendar.roleoptional');
       opts['NON-PARTICIPANT'] = rcmail.gettext('calendar.rolenonparticipant');
 
       if (data.cutype != 'RESOURCE')
         opts['CHAIR'] =  rcmail.gettext('calendar.rolechair');
 
       if (organizer && !readonly)
           dispname = rcmail.env['identities-selector'];
       
       var select = '<select class="edit-attendee-role"' + (organizer || readonly ? ' disabled="true"' : '') + '>';
       for (var r in opts)
         select += '<option value="'+ r +'" class="' + r.toLowerCase() + '"' + (data.role == r ? ' selected="selected"' : '') +'>' + Q(opts[r]) + '</option>';
       select += '</select>';
       
       // availability
       var avail = data.email ? 'loading' : 'unknown';
 
       // delete icon
       var icon = rcmail.env.deleteicon ? '<img src="' + rcmail.env.deleteicon + '" alt="" />' : rcmail.gettext('delete');
       var dellink = '<a href="#delete" class="iconlink delete deletelink" title="' + Q(rcmail.gettext('delete')) + '">' + icon + '</a>';
       
       var html = '<td class="role">' + select + '</td>' +
         '<td class="name">' + dispname + '</td>' +
         '<td class="availability"><img src="./program/resources/blank.gif" class="availabilityicon ' + avail + '" data-email="' + data.email + '" /></td>' +
         '<td class="confirmstate"><span class="' + String(data.status).toLowerCase() + '" title="' + Q(data.status || '') + '">' + Q(data.status || '') + '</span></td>' +
         '<td class="options">' + (organizer || readonly ? '' : dellink) + '</td>';
 
       var table = calendar.resources && data.cutype == 'RESOURCE' ? resources_list : attendees_list;
       var tr = $('<tr>')
         .addClass(String(data.role).toLowerCase())
         .html(html)
         .appendTo(table);
 
       tr.find('a.deletelink').click({ id:(data.email || data.name) }, function(e) { remove_attendee(this, e.data.id); return false; });
       tr.find('a.mailtolink').click(function(e) { rcmail.redirect(rcmail.url('mail/compose', { _to:this.href.substr(7) })); return false; });
 
       // select organizer identity
       if (data.identity_id)
         $('#edit-identities-list').val(data.identity_id);
       
       // check free-busy status
       if (avail == 'loading') {
         check_freebusy_status(tr.find('img.availabilityicon'), data.email, me.selected_event);
       }
       
       event_attendees.push(data);
       return true;
     };
     
     // iterate over all attendees and update their free-busy status display
     var update_freebusy_status = function(event)
     {
       attendees_list.find('img.availabilityicon').each(function(i,v) {
         var email, icon = $(this);
         if (email = icon.attr('data-email'))
           check_freebusy_status(icon, email, event);
       });
       
       freebusy_ui.needsupdate = false;
     };
     
     // load free-busy status from server and update icon accordingly
     var check_freebusy_status = function(icon, email, event)
     {
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { freebusy:false };
       if (!calendar.freebusy) {
         $(icon).removeClass().addClass('availabilityicon unknown');
         return;
       }
       
       icon = $(icon).removeClass().addClass('availabilityicon loading');
       
       $.ajax({
         type: 'GET',
         dataType: 'html',
         url: rcmail.url('freebusy-status'),
         data: { email:email, start:date2servertime(clone_date(event.start, event.allDay?1:0)), end:date2servertime(clone_date(event.end, event.allDay?2:0)), _remote: 1 },
         success: function(status){
           icon.removeClass('loading').addClass(String(status).toLowerCase());
         },
         error: function(){
           icon.removeClass('loading').addClass('unknown');
         }
       });
     };
     
     // remove an attendee from the list
     var remove_attendee = function(elem, id)
     {
       $(elem).closest('tr').remove();
       event_attendees = $.grep(event_attendees, function(data){ return (data.name != id && data.email != id) });
     };
 
     // open a dialog to display detailed free-busy information and to find free slots
     var event_resources_dialog = function()
     {
       var $dialog = $('#eventresourcesdialog'),
         event = me.selected_event;
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
   
       // dialog buttons
       var buttons = {};
   
       buttons[rcmail.gettext('addresource', 'calendar')] = function() {
         rcmail.command('add-resource');
       };
   
       buttons[rcmail.gettext('close')] = function() {
         $dialog.dialog("close");
       };
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: true,
         closeOnEscape: true,
         title: rcmail.gettext('findresources', 'calendar'),
         close: function() {
           $dialog.dialog('destroy').hide();
         },
         buttons: buttons,
         width: 900,
         height: 500
       }).show();
 
       // define add-button as main action
       $('.ui-dialog-buttonset .ui-button', $dialog.parent()).first().addClass('mainaction').attr('id', 'rcmbtncalresadd');
 
       me.dialog_resize($dialog.get(0), 540, Math.min(1000, $(window).width() - 50));
 
       // initialize the treelist widget
       if (!resources_treelist) {
         resources_treelist = new rcube_treelist_widget(rcmail.gui_objects.resourceslist, {
           id_prefix: 'rcres',
           id_encode: rcmail.html_identifier_encode,
           id_decode: rcmail.html_identifier_decode,
           selectable: true
         });
         resources_treelist.addEventListener('select', function(node) {
           if (resources_data[node.id]) {
             resource_showinfo(resources_data[node.id]);
             rcmail.enable_command('add-resource', me.selected_event ? true : false);
           }
           else {
             rcmail.enable_command('add-resource', false);
             $(rcmail.gui_objects.resourceinfo).hide();
             $(rcmail.gui_objects.resourceownerinfo).hide();
           }
         });
 
         // fetch (all) resource data from server
         me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
         rcmail.http_request('resources-list', {}, me.loading_lock);
 
         // register button
         rcmail.register_button('add-resource', 'rcmbtncalresadd', 'uibutton');
       }
       else {
         resources_treelist.select('__none__');
       }
     };
 
     // render the resource details UI box
     var resource_showinfo = function(resource)
     {
       // inline function to render a resource attribute
       function render_attrib(value) {
         if (typeof value == 'boolean') {
           return value ? rcmail.get_label('yes') : rcmail.get_label('no');
         }
 
         return value;
       }
 
       if (rcmail.gui_objects.resourceinfo) {
         var tr, table = $(rcmail.gui_objects.resourceinfo).show().find('tbody').html(''),
           attribs = $.extend({ name:resource.name }, resource.attributes||{})
           attribs.description = resource.description;
 
         for (var k in attribs) {
           if (typeof attribs[k] == 'undefined')
             continue;
           table.append($('<tr>').addClass(k)
             .append('<td class="title">' + Q(ucfirst(rcmail.get_label(k, 'calendar'))) + '</td>')
             .append('<td class="value">' + text2html(render_attrib(attribs[k])) + '</td>')
           );
         }
 
         $(rcmail.gui_objects.resourceownerinfo).hide();
 
         if (resource.owner) {
-          // fetch owner data from server
-          me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
-          rcmail.http_request('resources-owner', { _id: resource.owner }, me.loading_lock);
+          // display cached data
+          if (resource_owners[resource.owner]) {
+            resource_owner_load(resource_owners[resource.owner]);
+          }
+          else {
+            // fetch owner data from server
+            me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
+            rcmail.http_request('resources-owner', { _id: resource.owner }, me.loading_lock);
+          }
         }
       }
     };
 
     // callback from server for resource listing
     var resource_data_load = function(data)
     {
       data.sort(function(a,b) {
         var j = a._type == 'collection' ? 1 : 0,
             k = b._type == 'collection' ? 1 : 0;
         return k != j ? (j - k) : (a.name < b.name ? 1 : 0);
       });
 
       // assign parent-relations
       $.each(data, function(i, rec) {
         resources_data[rec.dn] = rec;
         resources_index.push(rec.dn);
 
         if (rec.members) {
           $.each(rec.members, function(j, m){
             resources_data[m].parent_id = rec.dn;
           });
         }
       });
 
       resources_index.reverse();
       resource_render_list(resources_index);
       rcmail.set_busy(false, null, me.loading_lock);
     };
 
     // renders the given list of resource records into the treelist
     var resource_render_list = function(index) {
       var rec, link;
 
       resources_treelist.reset();
 
       $.each(index, function(i, dn) {
         if (rec = resources_data[dn]) {
           link = $('<a>').attr('href', '#')
             .attr('rel', rec.dn)
             .html(Q(rec.name));
 
           resources_treelist.insert({ id:rec.dn, html:link, classes:[rec._type], collapsed:true }, rec.parent_id, false);
         }
       });
     };
 
     // callback from server for owner information display
     var resource_owner_load = function(data)
     {
       if (data) {
-        // TODO: cache this!
+        // cache this!
+        resource_owners[data.ID] = data;
 
         var table = $(rcmail.gui_objects.resourceownerinfo).find('tbody').html('');
 
         for (var k in data) {
-          if (k == 'event')
+          if (k == 'event' || k == 'ID')
             continue;
 
           table.append($('<tr>').addClass(k)
             .append('<td class="title">' + Q(ucfirst(rcmail.get_label('owner'+k, 'calendar'))) + '</td>')
             .append('<td class="value">' + text2html(data[k]) + '</td>')
           );
         }
 
         table.parent().show();
       }
     }
 
     // quick-filter the loaded resource data
     var resource_search = function()
     {
       var dataset, rec, q = $('#resourcesearchbox').val().toLowerCase();
       if (q.length && resources_data) {
         dataset = [];
 
         // search by iterating over all resource records
         for (var dn in resources_data) {
           rec = resources_data[dn];
           if (String(rec.name).toLowerCase().indexOf(q) >= 0) {
             dataset.push(rec.dn);
           }
         }
 
         resource_render_list(dataset);
 
         // select single match
         if (dataset.length == 1) {
           resources_treelist.select(dataset[0]);
         }
       }
       else {
         $('#resourcesearchbox').val('');
       }
     };
 
     // 
     var reset_resource_search = function()
     {
       $('#resourcesearchbox').val('').focus();
       resource_render_list(resources_index);
     };
 
     // 
     var add_resource2event = function()
     {
       var resource = resources_data[resources_treelist.get_selection()];
       if (resource) {
         if (add_attendee($.extend({ role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' }, resource)))
           rcmail.display_message(rcmail.get_label('resourceadded', 'calendar'), 'confirmation');
       }
     }
 
     // when the user accepts or declines an event invitation
     var event_rsvp = function(response)
     {
       if (me.selected_event && me.selected_event.attendees && response) {
         // update attendee status
         for (var data, i=0; i < me.selected_event.attendees.length; i++) {
           data = me.selected_event.attendees[i];
           if (settings.identity.emails.indexOf(';'+String(data.email).toLowerCase()) >= 0)
             data.status = response.toUpperCase();
         }
         event_show_dialog(me.selected_event);
         
         // submit status change to server
         me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
         rcmail.http_post('event', { action:'rsvp', e:me.selected_event, status:response });
       }
     }
     
     // post the given event data to server
     var update_event = function(action, data)
     {
       me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
       rcmail.http_post('calendar/event', { action:action, e:data });
       
       // render event temporarily into the calendar
       if ((data.start && data.end) || data.id) {
         var event = data.id ? $.extend(fc.fullCalendar('clientEvents', function(e){ return e.id == data.id; })[0], data) : data;
         if (data.start)
           event.start = data.start;
         if (data.end)
           event.end = data.end;
         if (data.allday !== undefined)
           event.allDay = data.allday;
         event.editable = false;
         event.temp = true;
         event.className = 'fc-event-cal-'+data.calendar+' fc-event-temp';
         fc.fullCalendar(data.id ? 'updateEvent' : 'renderEvent', event);
       }
     };
 
     // mouse-click handler to check if the show dialog is still open and prevent default action
     var dialog_check = function(e)
     {
       var showd = $("#eventshow");
       if (showd.is(':visible') && !$(e.target).closest('.ui-dialog').length) {
         showd.dialog('close');
         e.stopImmediatePropagation();
         ignore_click = true;
         return false;
       }
       else if (ignore_click) {
         window.setTimeout(function(){ ignore_click = false; }, 20);
         return false;
       }
       return true;
     };
 
     // display confirm dialog when modifying/deleting an event
     var update_event_confirm = function(action, event, data)
     {
       if (!data) data = event;
       var decline = false, notify = false, html = '', cal = me.calendars[event.calendar];
       
       // event has attendees, ask whether to notify them
       if (has_attendees(event)) {
         if (is_organizer(event)) {
           notify = true;
           html += '<div class="message">' +
             '<label><input class="confirm-attendees-donotify" type="checkbox" checked="checked" value="1" name="notify" />&nbsp;' +
             rcmail.gettext((action == 'remove' ? 'sendcancellation' : 'sendnotifications'), 'calendar') + 
             '</label></div>';
         }
         else if (action == 'remove' && is_attendee(event)) {
           decline = true;
           html += '<div class="message">' +
             '<label><input class="confirm-attendees-decline" type="checkbox" checked="checked" value="1" name="decline" />&nbsp;' +
             rcmail.gettext('itipdeclineevent', 'calendar') + 
             '</label></div>';
         }
         else {
           html += '<div class="message">' + rcmail.gettext('localchangeswarning', 'calendar') + '</div>';
         }
       }
       
       // recurring event: user needs to select the savemode
       if (event.recurrence) {
         html += '<div class="message"><span class="ui-icon ui-icon-alert"></span>' +
           rcmail.gettext((action == 'remove' ? 'removerecurringeventwarning' : 'changerecurringeventwarning'), 'calendar') + '</div>' +
           '<div class="savemode">' +
             '<a href="#current" class="button">' + rcmail.gettext('currentevent', 'calendar') + '</a>' +
             '<a href="#future" class="button">' + rcmail.gettext('futurevents', 'calendar') + '</a>' +
             '<a href="#all" class="button">' + rcmail.gettext('allevents', 'calendar') + '</a>' +
             (action != 'remove' ? '<a href="#new" class="button">' + rcmail.gettext('saveasnew', 'calendar') + '</a>' : '') +
           '</div>';
       }
       
       // show dialog
       if (html) {
         var $dialog = $('<div>').html(html);
       
         $dialog.find('a.button').button().click(function(e){
           data._savemode = String(this.href).replace(/.+#/, '');
           if ($dialog.find('input.confirm-attendees-donotify').get(0))
             data._notify = notify && $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
           if (decline && $dialog.find('input.confirm-attendees-decline:checked'))
             data.decline = 1;
           update_event(action, data);
           $dialog.dialog("destroy").hide();
           return false;
         });
         
         var buttons = [];
 
         if (!event.recurrence) {
           buttons.push({
             text: rcmail.gettext((action == 'remove' ? 'remove' : 'save'), 'calendar'),
             click: function() {
               data._notify = notify && $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
               data.decline = decline && $dialog.find('input.confirm-attendees-decline:checked').length ? 1 : 0;
               update_event(action, data);
               $(this).dialog("close");
             }
           });
         }
 
         buttons.push({
           text: rcmail.gettext('cancel', 'calendar'),
           click: function() {
             $(this).dialog("close");
           }
         });
 
         $dialog.dialog({
           modal: true,
           width: 460,
           dialogClass: 'warning',
           title: rcmail.gettext((action == 'remove' ? 'removeeventconfirm' : 'changeeventconfirm'), 'calendar'),
           buttons: buttons,
           open: function() {
             $dialog.parent().find('.ui-button').first().focus();
           },
           close: function(){
             $dialog.dialog("destroy").hide();
             if (!rcmail.busy)
               fc.fullCalendar('refetchEvents');
           }
         }).addClass('event-update-confirm').show();
         
         return false;
       }
       // show regular confirm box when deleting
       else if (action == 'remove' && !cal.undelete) {
         if (!confirm(rcmail.gettext('deleteventconfirm', 'calendar')))
           return false;
       }
 
       // do update
       update_event(action, data);
       
       return true;
     };
 
     var update_agenda_toolbar = function()
     {
       $('#agenda-listrange').val(fc.fullCalendar('option', 'listRange'));
       $('#agenda-listsections').val(fc.fullCalendar('option', 'listSections'));
     }
 
     /*** fullcalendar event handlers ***/
 
     var fc_event_render = function(event, element, view) {
       if (view.name != 'list' && view.name != 'table') {
         var prefix = event.sensitivity && event.sensitivity != 'public' ? String(sensitivitylabels[event.sensitivity]).toUpperCase()+': ' : '';
         element.attr('title', prefix + event.title);
       }
       if (view.name != 'month') {
         if (event.location) {
           element.find('div.fc-event-title').after('<div class="fc-event-location">@&nbsp;' + Q(event.location) + '</div>');
         }
         if (event.sensitivity && event.sensitivity != 'public')
           element.find('div.fc-event-time').append('<i class="fc-icon-sensitive"></i>');
         if (event.recurrence)
           element.find('div.fc-event-time').append('<i class="fc-icon-recurring"></i>');
         if (event.alarms)
           element.find('div.fc-event-time').append('<i class="fc-icon-alarms"></i>');
       }
     };
 
 
     /*** public methods ***/
 
     /**
      * Remove saving lock and free the UI for new input
      */
     this.unlock_saving = function()
     {
         if (me.saving_lock)
             rcmail.set_busy(false, null, me.saving_lock);
     };
 
     // opens calendar day-view in a popup
     this.fisheye_view = function(date)
     {
       $('#fish-eye-view:ui-dialog').dialog('close');
       
       // create list of active event sources
       var src, cals = {}, sources = [];
       for (var id in this.calendars) {
         src = $.extend({}, this.calendars[id]);
         src.editable = false;
         src.url = null;
         src.events = [];
 
         if (src.active) {
           cals[id] = src;
           sources.push(src);
         }
       }
       
       // copy events already loaded
       var events = fc.fullCalendar('clientEvents');
       for (var event, i=0; i< events.length; i++) {
         event = events[i];
         if (event.source && (src = cals[event.source.id])) {
           src.events.push(event);
         }
       }
       
       var h = $(window).height() - 50;
       var dialog = $('<div>')
         .attr('id', 'fish-eye-view')
         .dialog({
           modal: true,
           width: 680,
           height: h,
           title: $.fullCalendar.formatDate(date, 'dddd ' + settings['date_long']),
           close: function(){
             dialog.dialog("destroy");
             me.fisheye_date = null;
           }
         })
         .fullCalendar({
           header: { left: '', center: '', right: '' },
           height: h - 50,
           defaultView: 'agendaDay',
           date: date.getDate(),
           month: date.getMonth(),
           year: date.getFullYear(),
           ignoreTimezone: true,  // will treat the given date strings as in local (browser's) timezone
           eventSources: sources,
           monthNames : settings['months'],
           monthNamesShort : settings['months_short'],
           dayNames : settings['days'],
           dayNamesShort : settings['days_short'],
           firstDay : settings['first_day'],
           firstHour : settings['first_hour'],
           slotMinutes : 60/settings['timeslots'],
           timeFormat: { '': settings['time_format'] },
           axisFormat : settings['time_format'],
           columnFormat: { day: 'dddd ' + settings['date_short'] },
           titleFormat: { day: 'dddd ' + settings['date_long'] },
           allDayText: rcmail.gettext('all-day', 'calendar'),
           currentTimeIndicator: settings.time_indicator,
           eventRender: fc_event_render,
           eventClick: function(event) {
             event_show_dialog(event);
           }
         });
         
         this.fisheye_date = date;
     };
 
     //public method to show the print dialog.
     this.print_calendars = function(view)
     {
       if (!view) view = fc.fullCalendar('getView').name;
       var date = fc.fullCalendar('getDate') || new Date();
       var range = fc.fullCalendar('option', 'listRange');
       var sections = fc.fullCalendar('option', 'listSections');
       rcmail.open_window(rcmail.url('print', { view: view, date: date2unixtime(date), range: range, sections: sections, search: this.search_query }), true, true);
     };
 
     // public method to bring up the new event dialog
     this.add_event = function(templ) {
       if (this.selected_calendar) {
         var now = new Date();
         var date = fc.fullCalendar('getDate');
         if (typeof date != 'Date')
           date = now;
         date.setHours(now.getHours()+1);
         date.setMinutes(0);
         var end = new Date(date.getTime());
         end.setHours(date.getHours()+1);
         event_edit_dialog('new', $.extend({ start:date, end:end, allDay:false, calendar:this.selected_calendar }, templ || {}));
       }
     };
 
     // delete the given event after showing a confirmation dialog
     this.delete_event = function(event) {
       // show confirm dialog for recurring events, use jquery UI dialog
       return update_event_confirm('remove', event, { id:event.id, calendar:event.calendar, attendees:event.attendees });
     };
     
     // opens a jquery UI dialog with event properties (or empty for creating a new calendar)
     this.calendar_edit_dialog = function(calendar)
     {
       // close show dialog first
       var $dialog = $("#calendarform");
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
       
       if (!calendar)
         calendar = { name:'', color:'cc0000', editable:true, showalarms:true };
       
       var form, name, color, alarms;
       
       $dialog.html(rcmail.get_label('loading'));
       $.ajax({
         type: 'GET',
         dataType: 'html',
         url: rcmail.url('calendar'),
         data: { action:(calendar.id ? 'form-edit' : 'form-new'), c:{ id:calendar.id } },
         success: function(data) {
           $dialog.html(data);
           // resize and reposition dialog window
           form = $('#calendarpropform');
           me.dialog_resize('#calendarform', form.height(), form.width());
           name = $('#calendar-name').prop('disabled', !calendar.editable).val(calendar.editname || calendar.name);
           color = $('#calendar-color').val(calendar.color).miniColors({ value: calendar.color, colorValues:rcmail.env.mscolors });
           alarms = $('#calendar-showalarms').prop('checked', calendar.showalarms).get(0);
           name.select();
         }
       });
 
       // dialog buttons
       var buttons = {};
       
       buttons[rcmail.gettext('save', 'calendar')] = function() {
         // form is not loaded
         if (!form || !form.length)
           return;
           
         // TODO: do some input validation
         if (!name.val() || name.val().length < 2) {
           alert(rcmail.gettext('invalidcalendarproperties', 'calendar'));
           name.select();
           return;
         }
         
         // post data to server
         var data = form.serializeJSON();
         if (data.color)
           data.color = data.color.replace(/^#/, '');
         if (calendar.id)
           data.id = calendar.id;
         if (alarms)
           data.showalarms = alarms.checked ? 1 : 0;
 
         me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
         rcmail.http_post('calendar', { action:(calendar.id ? 'edit' : 'new'), c:data });
         $dialog.dialog("close");
       };
 
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: true,
         closeOnEscape: false,
         title: rcmail.gettext((calendar.id ? 'editcalendar' : 'createcalendar'), 'calendar'),
         open: function() {
           $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().addClass('mainaction');
         },
         close: function() {
           $dialog.html('').dialog("destroy").hide();
         },
         buttons: buttons,
         minWidth: 400,
         width: 420
       }).show();
 
     };
 
     this.calendar_remove = function(calendar)
     {
       if (confirm(rcmail.gettext(calendar.children ? 'deletecalendarconfirmrecursive' : 'deletecalendarconfirm', 'calendar'))) {
         rcmail.http_post('calendar', { action:'remove', c:{ id:calendar.id } });
         return true;
       }
       return false;
     };
 
     this.calendar_destroy_source = function(id)
     {
       var delete_ids = [];
 
       if (this.calendars[id]) {
         // find sub-calendars
         if (this.calendars[id].children) {
           for (var child_id in this.calendars) {
             if (String(child_id).indexOf(id) == 0)
               delete_ids.push(child_id);
           }
         }
         else {
           delete_ids.push(id);
         }
       }
 
       // delete all calendars in the list
       for (var i=0; i < delete_ids.length; i++) {
         id = delete_ids[i];
         fc.fullCalendar('removeEventSource', this.calendars[id]);
         $(rcmail.get_folder_li(id, 'rcmlical')).remove();
         $('#edit-calendar option[value="'+id+'"]').remove();
         delete this.calendars[id];
       }
     };
 
     // open a dialog to upload an .ics file with events to be imported
     this.import_events = function(calendar)
     {
       // close show dialog first
       var $dialog = $("#eventsimport"),
         form = rcmail.gui_objects.importform;
       
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
       
       if (calendar)
         $('#event-import-calendar').val(calendar.id);
       
       var buttons = {};
       buttons[rcmail.gettext('import', 'calendar')] = function() {
         if (form && form.elements._data.value) {
           rcmail.async_upload_form(form, 'import_events', function(e) {
             rcmail.set_busy(false, null, me.saving_lock);
             $('.ui-dialog-buttonpane button', $dialog.parent()).button('enable');
 
             // display error message if no sophisticated response from server arrived (e.g. iframe load error)
             if (me.import_succeeded === null)
               rcmail.display_message(rcmail.get_label('importerror', 'calendar'), 'error');
           });
 
           // display upload indicator (with extended timeout)
           var timeout = rcmail.env.request_timeout;
           rcmail.env.request_timeout = 600;
           me.import_succeeded = null;
           me.saving_lock = rcmail.set_busy(true, 'uploading');
           $('.ui-dialog-buttonpane button', $dialog.parent()).button('disable');
 
           // restore settings
           rcmail.env.request_timeout = timeout;
         }
       };
       
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
       
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: false,
         closeOnEscape: false,
         title: rcmail.gettext('importevents', 'calendar'),
         open: function() {
           $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().addClass('mainaction');
         },
         close: function() {
           $('.ui-dialog-buttonpane button', $dialog.parent()).button('enable');
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
         width: 520
       }).show();
       
     };
 
     // callback from server if import succeeded
     this.import_success = function(p)
     {
       this.import_succeeded = true;
       $("#eventsimport:ui-dialog").dialog('close');
       rcmail.set_busy(false, null, me.saving_lock);
       rcmail.gui_objects.importform.reset();
 
       if (p.refetch)
         this.refresh(p);
     };
 
     // callback from server to report errors on import
     this.import_error = function(p)
     {
       this.import_succeeded = false;
       rcmail.set_busy(false, null, me.saving_lock);
       rcmail.display_message(p.message || rcmail.get_label('importerror', 'calendar'), 'error');
     }
 
     // open a dialog to select calendars for export
     this.export_events = function(calendar)
     {
       // close show dialog first
       var $dialog = $("#eventsexport"),
         form = rcmail.gui_objects.exportform;
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       if (calendar)
         $('#event-export-calendar').val(calendar.id);
 
       $('#event-export-range').change(function(e){
         var custom = $('option:selected', this).val() == 'custom',
           input = $('#event-export-startdate')
         input.parent()[(custom?'show':'hide')]();
         if (custom)
           input.select();
       })
       
       var buttons = {};
       buttons[rcmail.gettext('export', 'calendar')] = function() {
         if (form) {
           var start = 0, range = $('#event-export-range option:selected', this).val(),
             source = $('#event-export-calendar option:selected').val(),
             attachmt = $('#event-export-attachments').get(0).checked;
 
           if (range == 'custom')
             start = date2unixtime(parse_datetime('00:00', $('#event-export-startdate').val()));
           else if (range > 0)
             start = 'today -' + range + ' months';
 
           rcmail.goto_url('export_events', { source:source, start:start, attachments:attachmt?1:0 });
         }
       };
       
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: false,
         closeOnEscape: false,
         title: rcmail.gettext('exporttitle', 'calendar'),
         open: function() {
           $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().addClass('mainaction');
         },
         close: function() {
           $('.ui-dialog-buttonpane button', $dialog.parent()).button('enable');
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
         width: 520
       }).show();
       
     };
 
     // show URL of the given calendar in a dialog box
     this.showurl = function(calendar)
     {
       var $dialog = $('#calendarurlbox');
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       if (calendar.feedurl) {
         if (calendar.caldavurl) {
           $('#caldavurl').val(calendar.caldavurl);
           $('#calendarcaldavurl').show();
         }
         else {
           $('#calendarcaldavurl').hide();
         }
 
         $dialog.dialog({
           resizable: true,
           closeOnEscape: true,
           title: rcmail.gettext('showurl', 'calendar'),
           close: function() {
             $dialog.dialog("destroy").hide();
           },
           width: 520
         }).show();
 
         $('#calfeedurl').val(calendar.feedurl).select();
       }
     };
 
     // refresh the calendar view after saving event data
     this.refresh = function(p)
     {
       var source = me.calendars[p.source];
 
       if (source && (p.refetch || (p.update && !source.active))) {
         // activate event source if new event was added to an invisible calendar
         if (!source.active) {
           source.active = true;
           fc.fullCalendar('addEventSource', source);
           $('#' + rcmail.get_folder_li(source.id, 'rcmlical').id + ' input').prop('checked', true);
         }
         else
           fc.fullCalendar('refetchEvents', source);
       }
       // add/update single event object
       else if (source && p.update) {
         var event = p.update;
         event.temp = false;
         event.editable = source.editable;
         var existing = fc.fullCalendar('clientEvents', event._id);
         if (existing.length) {
           $.extend(existing[0], event);
           fc.fullCalendar('updateEvent', existing[0]);
           // remove old recurrence instances
           if (event.recurrence && !event.recurrence_id)
             fc.fullCalendar('removeEvents', function(e){ return e._id.indexOf(event._id+'-') == 0; });
         }
         else {
           event.source = source;  // link with source
           fc.fullCalendar('renderEvent', event);
         }
         // refresh fish-eye view
         if (me.fisheye_date)
           me.fisheye_view(me.fisheye_date);
       }
       // refetch all calendars
       else if (p.refetch) {
         fc.fullCalendar('refetchEvents');
       }
 
       // remove temp events
       fc.fullCalendar('removeEvents', function(e){ return e.temp; });
     };
 
     // modify query parameters for refresh requests
     this.before_refresh = function(query)
     {
       var view = fc.fullCalendar('getView');
 
       query.start = date2unixtime(view.visStart);
       query.end = date2unixtime(view.visEnd);
 
       if (this.search_query)
         query.q = this.search_query;
 
       return query;
     };
 
     // reload the calendar view by keeping the current date/view selection
     this.reload_view = function()
     {
       var query = { view: fc.fullCalendar('getView').name },
         date = fc.fullCalendar('getDate');
       if (date)
         query.date = date2unixtime(date);
       rcmail.redirect(rcmail.url('', query));
     }
 
     // update browser location to remember current view
     this.update_state = function()
     {
       var query = { view: current_view },
         date = fc.fullCalendar('getDate');
       if (date)
         query.date = date2unixtime(date);
 
       if (window.history.replaceState)
         window.history.replaceState({}, document.title, rcmail.url('', query).replace('&_action=', ''));
     };
 
     this.resource_search = resource_search;
     this.reset_resource_search = reset_resource_search;
     this.add_resource2event = add_resource2event;
     this.resource_data_load = resource_data_load;
     this.resource_owner_load = resource_owner_load;
 
 
     /***  event searching  ***/
 
     // execute search
     this.quicksearch = function()
     {
       if (rcmail.gui_objects.qsearchbox) {
         var q = rcmail.gui_objects.qsearchbox.value;
         if (q != '') {
           var id = 'search-'+q;
           var sources = [];
           
           if (this._search_message)
             rcmail.hide_message(this._search_message);
           
           for (var sid in this.calendars) {
             if (this.calendars[sid]) {
               this.calendars[sid].url = this.calendars[sid].url.replace(/&q=.+/, '') + '&q='+escape(q);
               sources.push(sid);
             }
           }
           id += '@'+sources.join(',');
           
           // ignore if query didn't change
           if (this.search_request == id) {
             return;
           }
           // remember current view
           else if (!this.search_request) {
             this.default_view = fc.fullCalendar('getView').name;
           }
           
           this.search_request = id;
           this.search_query = q;
           
           // change to list view
           fc.fullCalendar('option', 'listSections', 'month')
             .fullCalendar('option', 'listRange', Math.max(60, settings['agenda_range']))
             .fullCalendar('changeView', 'table');
           
           update_agenda_toolbar();
           
           // refetch events with new url (if not already triggered by changeView)
           if (!this.is_loading)
             fc.fullCalendar('refetchEvents');
         }
         else  // empty search input equals reset
           this.reset_quicksearch();
       }
     };
 
     // reset search and get back to normal event listing
     this.reset_quicksearch = function()
     {
       $(rcmail.gui_objects.qsearchbox).val('');
       
       if (this._search_message)
         rcmail.hide_message(this._search_message);
       
       if (this.search_request) {
         // hide bottom links of agenda view
         fc.find('.fc-list-content > .fc-listappend').hide();
         
         // restore original event sources and view mode from fullcalendar
         fc.fullCalendar('option', 'listSections', settings['agenda_sections'])
           .fullCalendar('option', 'listRange', settings['agenda_range']);
         
         update_agenda_toolbar();
         
         for (var sid in this.calendars) {
           if (this.calendars[sid])
             this.calendars[sid].url = this.calendars[sid].url.replace(/&q=.+/, '');
         }
         if (this.default_view)
           fc.fullCalendar('changeView', this.default_view);
         
         if (!this.is_loading)
           fc.fullCalendar('refetchEvents');
         
         this.search_request = this.search_query = null;
       }
     };
 
     // callback if all sources have been fetched from server
     this.events_loaded = function(count)
     {
       var addlinks, append = '';
       
       // enhance list view when searching
       if (this.search_request) {
         if (!count) {
           this._search_message = rcmail.display_message(rcmail.gettext('searchnoresults', 'calendar'), 'notice');
           append = '<div class="message">' + rcmail.gettext('searchnoresults', 'calendar') + '</div>';
         }
         append += '<div class="fc-bottomlinks formlinks"></div>';
         addlinks = true;
       }
       
       if (fc.fullCalendar('getView').name == 'table') {
         var container = fc.find('.fc-list-content > .fc-listappend');
         if (append) {
           if (!container.length)
             container = $('<div class="fc-listappend"></div>').appendTo(fc.find('.fc-list-content'));
           container.html(append).show();
         }
         else if (container.length)
           container.hide();
         
         // add links to adjust search date range
         if (addlinks) {
           var lc = container.find('.fc-bottomlinks');
           $('<a>').attr('href', '#').html(rcmail.gettext('searchearlierdates', 'calendar')).appendTo(lc).click(function(){
             fc.fullCalendar('incrementDate', 0, -1, 0);
           });
           lc.append(" ");
           $('<a>').attr('href', '#').html(rcmail.gettext('searchlaterdates', 'calendar')).appendTo(lc).click(function(){
             var range = fc.fullCalendar('option', 'listRange');
             if (range < 90) {
               fc.fullCalendar('option', 'listRange', fc.fullCalendar('option', 'listRange') + 30).fullCalendar('render');
               update_agenda_toolbar();
             }
             else
               fc.fullCalendar('incrementDate', 0, 1, 0);
           });
         }
       }
       
       if (this.fisheye_date)
         this.fisheye_view(this.fisheye_date);
     };
 
     // resize and reposition (center) the dialog window
     this.dialog_resize = function(id, height, width)
     {
       var win = $(window), w = win.width(), h = win.height();
       $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) })
         .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
     };
 
     // adjust calendar view size
     this.view_resize = function()
     {
       var footer = fc.fullCalendar('getView').name == 'table' ? $('#agendaoptions').outerHeight() : 0;
       fc.fullCalendar('option', 'height', $('#calendar').height() - footer);
     };
 
 
     /***  startup code  ***/
 
     // create list of event sources AKA calendars
     this.calendars = {};
     var id, li, cal, active, color, brightness, event_sources = [];
     for (id in rcmail.env.calendars) {
       cal = rcmail.env.calendars[id];
       this.calendars[id] = $.extend({
         url: "./?_task=calendar&_action=load_events&source="+escape(id),
         editable: !cal.readonly,
         className: 'fc-event-cal-'+id,
         id: id
       }, cal);
 
       // choose black text color when background is bright, white otherwise
       if (color = settings.event_coloring % 2  ? '' : '#' + cal.color) {
         if (/^#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})$/i.test(color)) {
           // use information about brightness calculation found at
           // http://javascriptrules.com/2009/08/05/css-color-brightness-contrast-using-javascript/
           brightness = (parseInt(RegExp.$1, 16) * 299 + parseInt(RegExp.$2, 16) * 587 + parseInt(RegExp.$3, 16) * 114) / 1000;
           if (brightness > 125)
             this.calendars[id].textColor = 'black';
         }
       }
 
       this.calendars[id].color = color;
 
       if ((active = cal.active || false)) {
         event_sources.push(this.calendars[id]);
       }
 
       // init event handler on calendar list checkbox
       if ((li = rcmail.get_folder_li(id, 'rcmlical'))) {
         $('#'+li.id+' input').click(function(e){
           var id = $(this).data('id');
           if (me.calendars[id]) {  // add or remove event source on click
             var action;
             if (this.checked) {
               action = 'addEventSource';
               me.calendars[id].active = true;
             }
             else {
               action = 'removeEventSource';
               me.calendars[id].active = false;
             }
             
             // add/remove event source
             fc.fullCalendar(action, me.calendars[id]);
             rcmail.http_post('calendar', { action:'subscribe', c:{ id:id, active:me.calendars[id].active?1:0 } });
           }
         }).data('id', id).get(0).checked = active;
         
         $(li).click(function(e){
           var id = $(this).data('id');
           rcmail.select_folder(id, 'rcmlical');
           rcmail.enable_command('calendar-edit', true);
           rcmail.enable_command('calendar-remove', 'calendar-showurl', true);
           me.selected_calendar = id;
         })
         .dblclick(function(){ me.calendar_edit_dialog(me.calendars[me.selected_calendar]); })
         .data('id', id);
       }
       
       if (!cal.readonly && !this.selected_calendar) {
         this.selected_calendar = id;
         rcmail.enable_command('addevent', true);
       }
     }
     
     // select default calendar
     if (settings.default_calendar && this.calendars[settings.default_calendar] && !this.calendars[settings.default_calendar].readonly)
       this.selected_calendar = settings.default_calendar;
     
     var viewdate = new Date();
     if (rcmail.env.date)
       viewdate.setTime(fromunixtime(rcmail.env.date));
     
     // initalize the fullCalendar plugin
     var fc = $('#calendar').fullCalendar({
       header: {
         right: 'prev,next today',
         center: 'title',
         left: 'agendaDay,agendaWeek,month,table'
       },
       aspectRatio: 1,
       date: viewdate.getDate(),
       month: viewdate.getMonth(),
       year: viewdate.getFullYear(),
       ignoreTimezone: true,  // will treat the given date strings as in local (browser's) timezone
       height: $('#calendar').height(),
       eventSources: event_sources,
       monthNames : settings['months'],
       monthNamesShort : settings['months_short'],
       dayNames : settings['days'],
       dayNamesShort : settings['days_short'],
       firstDay : settings['first_day'],
       firstHour : settings['first_hour'],
       slotMinutes : 60/settings['timeslots'],
       timeFormat: {
         '': settings['time_format'],
         agenda: settings['time_format'] + '{ - ' + settings['time_format'] + '}',
         list: settings['time_format'] + '{ - ' + settings['time_format'] + '}',
         table: settings['time_format'] + '{ - ' + settings['time_format'] + '}'
       },
       axisFormat : settings['time_format'],
       columnFormat: {
         month: 'ddd', // Mon
         week: 'ddd ' + settings['date_short'], // Mon 9/7
         day: 'dddd ' + settings['date_short'],  // Monday 9/7
         table: settings['date_agenda']
       },
       titleFormat: {
         month: 'MMMM yyyy',
         week: settings['dates_long'],
         day: 'dddd ' + settings['date_long'],
         table: settings['dates_long']
       },
       listPage: 1,  // advance one day in agenda view
       listRange: settings['agenda_range'],
       listSections: settings['agenda_sections'],
       tableCols: ['handle', 'date', 'time', 'title', 'location'],
       defaultView: rcmail.env.view || settings['default_view'],
       allDayText: rcmail.gettext('all-day', 'calendar'),
       buttonText: {
         prev: (bw.ie6 ? '&nbsp;&lt;&lt;&nbsp;' : '&nbsp;&#9668;&nbsp;'),
         next: (bw.ie6 ? '&nbsp;&gt;&gt;&nbsp;' : '&nbsp;&#9658;&nbsp;'),
         today: settings['today'],
         day: rcmail.gettext('day', 'calendar'),
         week: rcmail.gettext('week', 'calendar'),
         month: rcmail.gettext('month', 'calendar'),
         table: rcmail.gettext('agenda', 'calendar')
       },
       listTexts: {
         until: rcmail.gettext('until', 'calendar'),
         past: rcmail.gettext('pastevents', 'calendar'),
         today: rcmail.gettext('today', 'calendar'),
         tomorrow: rcmail.gettext('tomorrow', 'calendar'),
         thisWeek: rcmail.gettext('thisweek', 'calendar'),
         nextWeek: rcmail.gettext('nextweek', 'calendar'),
         thisMonth: rcmail.gettext('thismonth', 'calendar'),
         nextMonth: rcmail.gettext('nextmonth', 'calendar'),
         future: rcmail.gettext('futureevents', 'calendar'),
         week: rcmail.gettext('weekofyear', 'calendar')
       },
       selectable: true,
       selectHelper: false,
       currentTimeIndicator: settings.time_indicator,
       loading: function(isLoading) {
         me.is_loading = isLoading;
         this._rc_loading = rcmail.set_busy(isLoading, 'loading', this._rc_loading);
         // trigger callback
         if (!isLoading)
           me.events_loaded($(this).fullCalendar('clientEvents').length);
       },
       // event rendering
       eventRender: fc_event_render,
       // render element indicating more (invisible) events
       overflowRender: function(data, element) {
         element.html(rcmail.gettext('andnmore', 'calendar').replace('$nr', data.count))
           .click(function(e){ me.fisheye_view(data.date); });
       },
       // callback for date range selection
       select: function(start, end, allDay, e, view) {
         var range_select = (!allDay || start.getDate() != end.getDate())
         if (dialog_check(e) && range_select)
           event_edit_dialog('new', { start:start, end:end, allDay:allDay, calendar:me.selected_calendar });
         if (range_select || ignore_click)
           view.calendar.unselect();
       },
       // callback for clicks in all-day box
       dayClick: function(date, allDay, e, view) {
         var now = new Date().getTime();
         if (now - day_clicked_ts < 400 && day_clicked == date.getTime()) {  // emulate double-click on day
           var enddate = new Date(); enddate.setTime(date.getTime() + DAY_MS - 60000);
           return event_edit_dialog('new', { start:date, end:enddate, allDay:allDay, calendar:me.selected_calendar });
         }
         
         if (!ignore_click) {
           view.calendar.gotoDate(date);
           if (day_clicked && new Date(day_clicked).getMonth() != date.getMonth())
             view.calendar.select(date, date, allDay);
         }
         day_clicked = date.getTime();
         day_clicked_ts = now;
       },
       // callback when a specific event is clicked
       eventClick: function(event) {
         if (!event.temp)
           event_show_dialog(event);
       },
       // callback when an event was dragged and finally dropped
       eventDrop: function(event, dayDelta, minuteDelta, allDay, revertFunc) {
         if (event.end == null || event.end.getTime() < event.start.getTime()) {
           event.end = new Date(event.start.getTime() + (allDay ? DAY_MS : HOUR_MS));
         }
         // moved to all-day section: set times to 12:00 - 13:00
         if (allDay && !event.allDay) {
           event.start.setHours(12);
           event.start.setMinutes(0);
           event.start.setSeconds(0);
           event.end.setHours(13);
           event.end.setMinutes(0);
           event.end.setSeconds(0);
         }
         // moved from all-day section: set times to working hours
         else if (event.allDay && !allDay) {
           var newstart = event.start.getTime();
           revertFunc();  // revert to get original duration
           var numdays = Math.max(1, Math.round((event.end.getTime() - event.start.getTime()) / DAY_MS)) - 1;
           event.start = new Date(newstart);
           event.end = new Date(newstart + numdays * DAY_MS);
           event.end.setHours(settings['work_end'] || 18);
           event.end.setMinutes(0);
           
           if (event.end.getTime() < event.start.getTime())
             event.end = new Date(newstart + HOUR_MS);
         }
         
         // send move request to server
         var data = {
           id: event.id,
           calendar: event.calendar,
           start: date2servertime(event.start),
           end: date2servertime(event.end),
           allday: allDay?1:0
         };
         update_event_confirm('move', event, data);
       },
       // callback for event resizing
       eventResize: function(event, delta) {
         // sanitize event dates
         if (event.allDay)
           event.start.setHours(12);
         if (!event.end || event.end.getTime() < event.start.getTime())
           event.end = new Date(event.start.getTime() + HOUR_MS);
 
         // send resize request to server
         var data = {
           id: event.id,
           calendar: event.calendar,
           start: date2servertime(event.start),
           end: date2servertime(event.end)
         };
         update_event_confirm('resize', event, data);
       },
       viewDisplay: function(view) {
         $('#agendaoptions')[view.name == 'table' ? 'show' : 'hide']();
         if (minical) {
           window.setTimeout(function(){ minical.datepicker('setDate', fc.fullCalendar('getDate')); }, exec_deferred);
           if (view.name != current_view)
             me.view_resize();
           current_view = view.name;
           me.update_state();
         }
       },
       viewRender: function(view) {
         if (fc && view.name == 'month')
           fc.fullCalendar('option', 'maxHeight', Math.floor((view.element.parent().height()-18) / 6) - 35);
       }
     });
 
     // format time string
     var formattime = function(hour, minutes, start) {
       var time, diff, unit, duration = '', d = new Date();
       d.setHours(hour);
       d.setMinutes(minutes);
       time = $.fullCalendar.formatDate(d, settings['time_format']);
       if (start) {
         diff = Math.floor((d.getTime() - start.getTime()) / 60000);
         if (diff > 0) {
           unit = 'm';
           if (diff >= 60) {
             unit = 'h';
             diff = Math.round(diff / 3) / 20;
           }
           duration = ' (' + diff + unit + ')';
         }
       }
       return [time, duration];
     };
 
     var autocomplete_times = function(p, callback) {
       /* Time completions */
       var result = [];
       var now = new Date();
       var st, start = (String(this.element.attr('id')).indexOf('endtime') > 0
         && (st = $('#edit-starttime').val())
         && $('#edit-startdate').val() == $('#edit-enddate').val())
         ? parse_datetime(st, '') : null;
       var full = p.term - 1 > 0 || p.term.length > 1;
       var hours = start ? start.getHours() :
         (full ? parse_datetime(p.term, '') : now).getHours();
       var step = 15;
       var minutes = hours * 60 + (full ? 0 : now.getMinutes());
       var min = Math.ceil(minutes / step) * step % 60;
       var hour = Math.floor(Math.ceil(minutes / step) * step / 60);
       // list hours from 0:00 till now
       for (var h = start ? start.getHours() : 0; h < hours; h++)
         result.push(formattime(h, 0, start));
       // list 15min steps for the next two hours
       for (; h < hour + 2 && h < 24; h++) {
         while (min < 60) {
           result.push(formattime(h, min, start));
           min += step;
         }
         min = 0;
       }
       // list the remaining hours till 23:00
       while (h < 24)
         result.push(formattime((h++), 0, start));
       
       return callback(result);
     };
 
     var autocomplete_open = function(event, ui) {
       // scroll to current time
       var $this = $(this);
       var widget = $this.autocomplete('widget');
       var menu = $this.data('autocomplete').menu;
       var amregex = /^(.+)(a[.m]*)/i;
       var pmregex = /^(.+)(a[.m]*)/i;
       var val = $(this).val().replace(amregex, '0:$1').replace(pmregex, '1:$1');
       var li, html;
       widget.css('width', '10em');
       widget.children().each(function(){
         li = $(this);
         html = li.children().first().html().replace(/\s+\(.+\)$/, '').replace(amregex, '0:$1').replace(pmregex, '1:$1');
         if (html.indexOf(val) == 0)
           menu._scrollIntoView(li);
       });
     };
 
     // if start date is changed, shift end date according to initial duration
     var shift_enddate = function(dateText) {
       var newstart = parse_datetime('0', dateText);
       var newend = new Date(newstart.getTime() + $('#edit-startdate').data('duration') * 1000);
       $('#edit-enddate').val($.fullCalendar.formatDate(newend, me.settings['date_format']));
       event_times_changed();
     };
 
     // Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
     // Uses the default $.datepicker.iso8601Week() function but takes firstDay setting into account.
     // This is a temporary fix until http://bugs.jqueryui.com/ticket/8420 is resolved.
     var iso8601Week = datepicker_settings.calculateWeek = function(date) {
       var mondayOffset = Math.abs(1 - datepicker_settings.firstDay);
       return $.datepicker.iso8601Week(new Date(date.getTime() + mondayOffset * 86400000));
     };
 
     var minical;
     var init_calendar_ui = function()
     {
       // initialize small calendar widget using jQuery UI datepicker
       minical = $('#datepicker').datepicker($.extend(datepicker_settings, {
         inline: true,
         showWeek: true,
         changeMonth: true,
         changeYear: true,
         onSelect: function(dateText, inst) {
           ignore_click = true;
           var d = minical.datepicker('getDate'); //parse_datetime('0:0', dateText);
           fc.fullCalendar('gotoDate', d).fullCalendar('select', d, d, true);
         },
         onChangeMonthYear: function(year, month, inst) {
           minical.data('year', year).data('month', month);
         },
         beforeShowDay: function(date) {
           var view = fc.fullCalendar('getView');
           var active = view.visStart && date.getTime() >= view.visStart.getTime() && date.getTime() < view.visEnd.getTime();
           return [ true, (active ? 'ui-datepicker-activerange ui-datepicker-active-' + view.name : ''), ''];
         }
       })) // set event handler for clicks on calendar week cell of the datepicker widget
         .click(function(e) {
           var cell = $(e.target);
           if (e.target.tagName == 'TD' && cell.hasClass('ui-datepicker-week-col')) {
             var base_date = minical.datepicker('getDate');
             if (minical.data('month'))
               base_date.setMonth(minical.data('month')-1);
             if (minical.data('year'))
               base_date.setYear(minical.data('year'));
             base_date.setHours(12);
             base_date.setDate(base_date.getDate() - ((base_date.getDay() + 6) % 7) + datepicker_settings.firstDay);
             var day_off = base_date.getDay() - datepicker_settings.firstDay;
             var base_kw = iso8601Week(base_date);
             var target_kw = parseInt(cell.html());
             var diff = (target_kw - base_kw) * 7 * DAY_MS;
             // select monday of the chosen calendar week
             var date = new Date(base_date.getTime() - day_off * DAY_MS + diff);
             fc.fullCalendar('gotoDate', date).fullCalendar('setDate', date).fullCalendar('changeView', 'agendaWeek');
             minical.datepicker('setDate', date);
           }
       });
 
       if (rcmail.env.date) {
         var viewdate = new Date();
         viewdate.setTime(fromunixtime(rcmail.env.date));
         minical.datepicker('setDate', viewdate);
       }
 
       // init event dialog
       $('#eventtabs').tabs({
         show: function(event, ui) {
           if (ui.panel.id == 'event-panel-attendees' || ui.panel.id == 'event-panel-resources') {
             var tab = ui.panel.id == 'event-panel-resources' ? 'resource' : 'attendee';
             $('#edit-'+tab+'-name').select();
             // update free-busy status if needed
             if (freebusy_ui.needsupdate && me.selected_event)
               update_freebusy_status(me.selected_event);
             // add current user as organizer if non added yet
             if (!event_attendees.length) {
               add_attendee($.extend({ role:'ORGANIZER' }, settings.identity));
               $('#edit-attendees-form .attendees-invitebox').show();
             }
           }
         }
       });
       $('#edit-enddate').datepicker(datepicker_settings);
       $('#edit-startdate').datepicker(datepicker_settings).datepicker('option', 'onSelect', shift_enddate).change(function(){ shift_enddate(this.value); });
       $('#edit-enddate').datepicker('option', 'onSelect', event_times_changed).change(event_times_changed);
       $('#edit-allday').click(function(){ $('#edit-starttime, #edit-endtime')[(this.checked?'hide':'show')](); event_times_changed(); });
 
       // configure drop-down menu on time input fields based on jquery UI autocomplete
       $('#edit-starttime, #edit-endtime, #eventedit input.edit-alarm-time')
         .attr('autocomplete', "off")
         .autocomplete({
           delay: 100,
           minLength: 1,
           source: autocomplete_times,
           open: autocomplete_open,
           change: event_times_changed,
           select: function(event, ui) {
             $(this).val(ui.item[0]);
             return false;
           }
         })
         .click(function() {  // show drop-down upon clicks
           $(this).autocomplete('search', $(this).val() ? $(this).val().replace(/\D.*/, "") : " ");
         }).each(function(){
           $(this).data('autocomplete')._renderItem = function(ul, item) {
             return $('<li>')
               .data('item.autocomplete', item)
               .append('<a>' + item[0] + item[1] + '</a>')
               .appendTo(ul);
             };
         });
 
       // register events on alarm fields
       init_alarms_edit('#eventedit');
 
       // toggle recurrence frequency forms
       $('#edit-recurrence-frequency').change(function(e){
         var freq = $(this).val().toLowerCase();
         $('.recurrence-form').hide();
         if (freq)
           $('#recurrence-form-'+freq+', #recurrence-form-until').show();
       });
       $('#edit-recurrence-enddate').datepicker(datepicker_settings).click(function(){ $("#edit-recurrence-repeat-until").prop('checked', true) });
       $('#edit-recurrence-repeat-times').change(function(e){ $('#edit-recurrence-repeat-count').prop('checked', true); });
 
       $('#event-export-startdate').datepicker(datepicker_settings);
 
       // init attendees autocompletion
       var ac_props;
       // parallel autocompletion
       if (rcmail.env.autocomplete_threads > 0) {
         ac_props = {
           threads: rcmail.env.autocomplete_threads,
           sources: rcmail.env.autocomplete_sources
         };
       }
       rcmail.init_address_input_events($('#edit-attendee-name'), ac_props);
       rcmail.addEventListener('autocomplete_insert', function(e){
         if (e.field.name == 'participant') {
           $('#edit-attendee-add').click();
         }
         else if (e.field.name == 'resource' && e.data && e.data.email) {
           add_attendee($.extend(e.data, { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' }));
           e.field.value = '';
         }
       });
 
       $('#edit-attendee-add').click(function(){
         var input = $('#edit-attendee-name');
         rcmail.ksearch_blur();
         if (add_attendees(input.val(), { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'INDIVIDUAL' })) {
           input.val('');
         }
       });
 
       rcmail.init_address_input_events($('#edit-resource-name'), { action:'calendar/resources-autocomplete' });
 
       $('#edit-resource-add').click(function(){
         var input = $('#edit-resource-name');
         rcmail.ksearch_blur();
         if (add_attendees(input.val(), { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' })) {
           input.val('');
         }
       });
       
       $('#edit-resource-find').click(function(){
         event_resources_dialog();
         return false;
       });
 
       // keep these two checkboxes in sync
       $('#edit-attendees-donotify, #edit-attendees-invite').click(function(){
         $('#edit-attendees-donotify, #edit-attendees-invite').prop('checked', this.checked);
       });
 
       $('#edit-attendee-schedule').click(function(){
         event_freebusy_dialog();
       });
 
       $('#shedule-freebusy-prev').html(bw.ie6 ? '&lt;&lt;' : '&#9668;').button().click(function(){ render_freebusy_grid(-1); });
       $('#shedule-freebusy-next').html(bw.ie6 ? '&gt;&gt;' : '&#9658;').button().click(function(){ render_freebusy_grid(1); }).parent().buttonset();
 
       $('#shedule-find-prev').button().click(function(){ freebusy_find_slot(-1); });
       $('#shedule-find-next').button().click(function(){ freebusy_find_slot(1); });
 
       $('#schedule-freebusy-workinghours').click(function(){
         freebusy_ui.workinhoursonly = this.checked;
         $('#workinghourscss').remove();
         if (this.checked)
           $('<style type="text/css" id="workinghourscss"> td.offhours { opacity:0.3; filter:alpha(opacity=30) } </style>').appendTo('head');
       });
 
       $('#event-rsvp input.button').click(function(){
         event_rsvp($(this).attr('rel'))
       });
 
       $('#agenda-listrange').change(function(e){
         settings['agenda_range'] = parseInt($(this).val());
         fc.fullCalendar('option', 'listRange', settings['agenda_range']).fullCalendar('render');
         // TODO: save new settings in prefs
       }).val(settings['agenda_range']);
 
       $('#agenda-listsections').change(function(e){
         settings['agenda_sections'] = $(this).val();
         fc.fullCalendar('option', 'listSections', settings['agenda_sections']).fullCalendar('render');
         // TODO: save new settings in prefs
       }).val(fc.fullCalendar('option', 'listSections'));
 
       // hide event dialog when clicking somewhere into document
       $(document).bind('mousedown', dialog_check);
 
       rcmail.set_busy(false, 'loading', ui_loading);
     }
 
     // initialize more UI elements (deferred)
     window.setTimeout(init_calendar_ui, exec_deferred);
 
     // add proprietary css styles if not IE
     if (!bw.ie)
       $('div.fc-content').addClass('rcube-fc-content');
 
     // IE supresses 2nd click event when double-clicking
     if (bw.ie && bw.vendver < 9) {
       $('div.fc-content').bind('dblclick', function(e){
         if (!$(this).hasClass('fc-widget-header') && fc.fullCalendar('getView').name != 'table') {
           var date = fc.fullCalendar('getDate');
           var enddate = new Date(); enddate.setTime(date.getTime() + DAY_MS - 60000);
           event_edit_dialog('new', { start:date, end:enddate, allDay:true, calendar:me.selected_calendar });
         }
       });
     }
 } // end rcube_calendar class
 
 
 /* calendar plugin initialization */
 window.rcmail && rcmail.addEventListener('init', function(evt) {
   // configure toolbar buttons
   rcmail.register_command('addevent', function(){ cal.add_event(); }, true);
   rcmail.register_command('print', function(){ cal.print_calendars(); }, true);
 
   // configure list operations
   rcmail.register_command('calendar-create', function(){ cal.calendar_edit_dialog(null); }, true);
   rcmail.register_command('calendar-edit', function(){ cal.calendar_edit_dialog(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('calendar-remove', function(){ cal.calendar_remove(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('events-import', function(){ cal.import_events(cal.calendars[cal.selected_calendar]); }, true);
   rcmail.register_command('calendar-showurl', function(){ cal.showurl(cal.calendars[cal.selected_calendar]); }, false);
  
   // search and export events
   rcmail.register_command('export', function(){ cal.export_events(cal.calendars[cal.selected_calendar]); }, true);
   rcmail.register_command('search', function(){ cal.quicksearch(); }, true);
   rcmail.register_command('reset-search', function(){ cal.reset_quicksearch(); }, true);
 
   // resource invitation dialog
   rcmail.register_command('search-resource', function(){ cal.resource_search(); }, true);
   rcmail.register_command('reset-resource-search', function(){ cal.reset_resource_search(); }, true);
   rcmail.register_command('add-resource', function(){ cal.add_resource2event(); }, false);
 
   // register callback commands
   rcmail.addEventListener('plugin.destroy_source', function(p){ cal.calendar_destroy_source(p.id); });
   rcmail.addEventListener('plugin.unlock_saving', function(p){ cal.unlock_saving(); });
   rcmail.addEventListener('plugin.refresh_calendar', function(p){ cal.refresh(p); });
   rcmail.addEventListener('plugin.import_success', function(p){ cal.import_success(p); });
   rcmail.addEventListener('plugin.import_error', function(p){ cal.import_error(p); });
   rcmail.addEventListener('plugin.reload_view', function(p){ cal.reload_view(p); });
   rcmail.addEventListener('plugin.resource_data', function(p){ cal.resource_data_load(p); });
   rcmail.addEventListener('plugin.resource_owner', function(p){ cal.resource_owner_load(p); });
   rcmail.addEventListener('requestrefresh', function(q){ return cal.before_refresh(q); });
 
   // let's go
   var cal = new rcube_calendar_ui($.extend(rcmail.env.calendar_settings, rcmail.env.libcal_settings));
 
   $(window).resize(function(e) {
     // check target due to bugs in jquery
     // http://bugs.jqueryui.com/ticket/7514
     // http://bugs.jquery.com/ticket/9841
     if (e.target == window) {
       cal.view_resize();
     }
   }).resize();
 
   // show calendars list when ready
   $('#calendars').css('visibility', 'inherit');
 
   // show toolbar
   $('#toolbar').show();
 
 });
diff --git a/plugins/calendar/drivers/kolab/kolab_driver.php b/plugins/calendar/drivers/kolab/kolab_driver.php
index 0b23f642..1bf4e17f 100644
--- a/plugins/calendar/drivers/kolab/kolab_driver.php
+++ b/plugins/calendar/drivers/kolab/kolab_driver.php
@@ -1,1390 +1,1391 @@
 <?php
 
 /**
  * Kolab driver for the Calendar plugin
  *
  * @version @package_version@
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  * @author Aleksander Machniak <machniak@kolabsys.com>
  *
  * Copyright (C) 2012-2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 require_once(dirname(__FILE__) . '/kolab_calendar.php');
 
 class kolab_driver extends calendar_driver
 {
   // features this backend supports
   public $alarms = true;
   public $attendees = true;
   public $freebusy = true;
   public $attachments = true;
   public $undelete = true;
   public $alarm_types = array('DISPLAY');
   public $categoriesimmutable = true;
 
   private $rc;
   private $cal;
   private $calendars;
   private $has_writeable = false;
   private $freebusy_trigger = false;
 
   /**
    * Default constructor
    */
   public function __construct($cal)
   {
     $this->cal = $cal;
     $this->rc = $cal->rc;
     $this->_read_calendars();
     
     $this->cal->register_action('push-freebusy', array($this, 'push_freebusy'));
     $this->cal->register_action('calendar-acl', array($this, 'calendar_acl'));
     
     $this->freebusy_trigger = $this->rc->config->get('calendar_freebusy_trigger', false);
 
     if (kolab_storage::$version == '2.0') {
         $this->alarm_types = array('DISPLAY');
         $this->alarm_absolute = false;
     }
 
     if ($this->rc->config->get('calendar_resources_directory')) {
       $this->resources = true;
     }
   }
 
 
   /**
    * Read available calendars from server
    */
   private function _read_calendars()
   {
     // already read sources
     if (isset($this->calendars))
       return $this->calendars;
 
     // get all folders that have "event" type, sorted by namespace/name
     $folders = kolab_storage::sort_folders(kolab_storage::get_folders('event'));
     $this->calendars = array();
 
     foreach ($folders as $folder) {
       $calendar = new kolab_calendar($folder->name, $this->cal);
       $this->calendars[$calendar->id] = $calendar;
       if (!$calendar->readonly)
         $this->has_writeable = true;
     }
 
     return $this->calendars;
   }
 
 
   /**
    * Get a list of available calendars from this source
    *
    * @param bool $active   Return only active calendars
    * @param bool $personal Return only personal calendars
    *
    * @return array List of calendars
    */
   public function list_calendars($active = false, $personal = false)
   {
     // attempt to create a default calendar for this user
     if (!$this->has_writeable) {
       if ($this->create_calendar(array('name' => 'Calendar', 'color' => 'cc0000'))) {
          unset($this->calendars);
         $this->_read_calendars();
       }
     }
 
     $folders = $this->filter_calendars(false, $active, $personal);
     $calendars = $names = array();
 
     // include virtual folders for a full folder tree
     if (!$active && !$personal && !$this->rc->output->ajax_call && in_array($this->rc->action, array('index','')))
       $folders = kolab_storage::folder_hierarchy($folders);
 
     foreach ($folders as $id => $cal) {
       $fullname = $cal->get_name();
       $listname = kolab_storage::folder_displayname($fullname, $names);
 
       // special handling for virtual folders
       if ($cal->virtual) {
         $calendars[$cal->id] = array(
           'id' => $cal->id,
           'name' => $fullname,
           'listname' => $listname,
           'virtual' => true,
           'readonly' => true,
         );
       }
       else {
         $calendars[$cal->id] = array(
           'id'       => $cal->id,
           'name'     => $fullname,
           'listname' => $listname,
           'editname' => $cal->get_foldername(),
           'color'    => $cal->get_color(),
           'readonly' => $cal->readonly,
           'showalarms' => $cal->alarms,
           'class_name' => $cal->get_namespace(),
           'default'  => $cal->storage->default,
           'active'   => $cal->storage->is_active(),
           'owner'    => $cal->get_owner(),
           'children' => true,  // TODO: determine if that folder indeed has child folders
           'caldavurl' => $cal->get_caldav_url(),
         );
       }
     }
 
     // append the virtual birthdays calendar
     if ($this->rc->config->get('calendar_contact_birthdays', false)) {
       $id = self::BIRTHDAY_CALENDAR_ID;
       $prefs = $this->rc->config->get('kolab_calendars', array());  // read local prefs
       if (!$active || $prefs[$id]['active']) {
         $calendars[$id] = array(
           'id'         => $id,
           'name'       => $this->cal->gettext('birthdays'),
           'listname'   => $this->cal->gettext('birthdays'),
           'color'      => $prefs[$id]['color'],
           'active'     => $prefs[$id]['active'],
           'showalarms' => (bool)$this->rc->config->get('calendar_birthdays_alarm_type'),
           'class_name' => 'birthdays',
           'readonly'   => true,
           'default'    => false,
           'children'   => false,
         );
       }
     }
 
     return $calendars;
   }
 
   /**
    * Get list of calendars according to specified filters
    *
    * @param bool $writeable Return only writeable calendars
    * @param bool $active   Return only active calendars
    * @param bool $personal Return only personal calendars
    *
    * @return array List of calendars
    */
   protected function filter_calendars($writeable = false, $active = false, $personal = false)
   {
     $calendars = array();
 
     $plugin = $this->rc->plugins->exec_hook('calendar_list_filter', array(
       'list' => $this->calendars, 'calendars' => $calendars,
       'writeable' => $writeable, 'active' => $active, 'personal' => $personal,
     ));
 
     if ($plugin['abort']) {
       return $plugin['calendars'];
     }
 
     foreach ($this->calendars as $cal) {
       if (!$cal->ready) {
         continue;
       }
       if ($writeable && $cal->readonly) {
         continue;
       }
       if ($active && !$cal->storage->is_active()) {
         continue;
       }
       if ($personal && $cal->get_namespace() != 'personal') {
         continue;
       }
       $calendars[$cal->id] = $cal;
     }
 
     return $calendars;
   }
 
   /**
    * Create a new calendar assigned to the current user
    *
    * @param array Hash array with calendar properties
    *    name: Calendar name
    *   color: The color of the calendar
    * @return mixed ID of the calendar on success, False on error
    */
   public function create_calendar($prop)
   {
     $prop['type'] = 'event';
     $prop['active'] = true;
     $prop['subscribed'] = true;
     $folder = kolab_storage::folder_update($prop);
 
     if ($folder === false) {
       $this->last_error = $this->cal->gettext(kolab_storage::$last_error);
       return false;
     }
 
     // create ID
     $id = kolab_storage::folder_id($folder);
 
     // save color in user prefs (temp. solution)
     $prefs['kolab_calendars'] = $this->rc->config->get('kolab_calendars', array());
 
     if (isset($prop['color']))
       $prefs['kolab_calendars'][$id]['color'] = $prop['color'];
     if (isset($prop['showalarms']))
       $prefs['kolab_calendars'][$id]['showalarms'] = $prop['showalarms'] ? true : false;
 
     if ($prefs['kolab_calendars'][$id])
       $this->rc->user->save_prefs($prefs);
 
     return $id;
   }
 
 
   /**
    * Update properties of an existing calendar
    *
    * @see calendar_driver::edit_calendar()
    */
   public function edit_calendar($prop)
   {
     if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
       $prop['oldname'] = $cal->get_realname();
       $newfolder = kolab_storage::folder_update($prop);
 
       if ($newfolder === false) {
         $this->last_error = $this->cal->gettext(kolab_storage::$last_error);
         return false;
       }
 
       // create ID
       $id = kolab_storage::folder_id($newfolder);
     }
     else {
       $id = $prop['id'];
     }
 
     // fallback to local prefs
     $prefs['kolab_calendars'] = $this->rc->config->get('kolab_calendars', array());
     unset($prefs['kolab_calendars'][$prop['id']]['color'], $prefs['kolab_calendars'][$prop['id']]['showalarms']);
 
     if (isset($prop['color']))
       $prefs['kolab_calendars'][$id]['color'] = $prop['color'];
 
     if (isset($prop['showalarms']) && $id == self::BIRTHDAY_CALENDAR_ID)
       $prefs['calendar_birthdays_alarm_type'] = $prop['showalarms'] ? $this->alarm_types[0] : '';
     else if (isset($prop['showalarms']))
       $prefs['kolab_calendars'][$id]['showalarms'] = $prop['showalarms'] ? true : false;
 
     if (!empty($prefs['kolab_calendars'][$id]))
       $this->rc->user->save_prefs($prefs);
 
     return true;
   }
 
 
   /**
    * Set active/subscribed state of a calendar
    *
    * @see calendar_driver::subscribe_calendar()
    */
   public function subscribe_calendar($prop)
   {
     if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
       return $cal->storage->activate($prop['active']);
     }
     else {
       // save state in local prefs
       $prefs['kolab_calendars'] = $this->rc->config->get('kolab_calendars', array());
       $prefs['kolab_calendars'][$prop['id']]['active'] = (bool)$prop['active'];
       $this->rc->user->save_prefs($prefs);
       return true;
     }
 
     return false;
   }
 
 
   /**
    * Delete the given calendar with all its contents
    *
    * @see calendar_driver::remove_calendar()
    */
   public function remove_calendar($prop)
   {
     if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
       $folder = $cal->get_realname();
       if (kolab_storage::folder_delete($folder)) {
         // remove color in user prefs (temp. solution)
         $prefs['kolab_calendars'] = $this->rc->config->get('kolab_calendars', array());
         unset($prefs['kolab_calendars'][$prop['id']]);
 
         $this->rc->user->save_prefs($prefs);
         return true;
       }
       else
         $this->last_error = kolab_storage::$last_error;
     }
 
     return false;
   }
 
 
   /**
    * Fetch a single event
    *
    * @see calendar_driver::get_event()
    * @return array Hash array with event properties, false if not found
    */
   public function get_event($event, $writeable = false, $active = false, $personal = false)
   {
     if (is_array($event)) {
       $id = $event['id'] ? $event['id'] : $event['uid'];
       $cal = $event['calendar'];
     }
     else {
       $id = $event;
     }
 
     if ($cal) {
       if ($storage = $this->calendars[$cal]) {
         return $storage->get_event($id);
       }
     }
     // iterate over all calendar folders and search for the event ID
     else {
       foreach ($this->filter_calendars($writeable, $active, $personal) as $calendar) {
         if ($result = $calendar->get_event($id)) {
           return $result;
         }
       }
     }
 
     return false;
   }
 
   /**
    * Add a single event to the database
    *
    * @see calendar_driver::new_event()
    */
   public function new_event($event)
   {
     if (!$this->validate($event))
       return false;
 
     $cid = $event['calendar'] ? $event['calendar'] : reset(array_keys($this->calendars));
     if ($storage = $this->calendars[$cid]) {
       // handle attachments to add
       if (!empty($event['attachments'])) {
         foreach ($event['attachments'] as $idx => $attachment) {
           // we'll read file contacts into memory, Horde/Kolab classes does the same
           // So we cannot save memory, rcube_imap class can do this better
           $event['attachments'][$idx]['content'] = $attachment['data'] ? $attachment['data'] : file_get_contents($attachment['path']);
         }
       }
 
       $success = $storage->insert_event($event);
       
       if ($success && $this->freebusy_trigger) {
         $this->rc->output->command('plugin.ping_url', array('action' => 'calendar/push-freebusy', 'source' => $storage->id));
         $this->freebusy_trigger = false; // disable after first execution (#2355)
       }
       
       return $success;
     }
 
     return false;
   }
 
   /**
    * Update an event entry with the given data
    *
    * @see calendar_driver::new_event()
    * @return boolean True on success, False on error
    */
   public function edit_event($event)
   {
     return $this->update_event($event);
   }
 
   /**
    * Move a single event
    *
    * @see calendar_driver::move_event()
    * @return boolean True on success, False on error
    */
   public function move_event($event)
   {
     if (($storage = $this->calendars[$event['calendar']]) && ($ev = $storage->get_event($event['id']))) {
       unset($ev['sequence']);
       return $this->update_event($event + $ev);
     }
 
     return false;
   }
 
   /**
    * Resize a single event
    *
    * @see calendar_driver::resize_event()
    * @return boolean True on success, False on error
    */
   public function resize_event($event)
   {
     if (($storage = $this->calendars[$event['calendar']]) && ($ev = $storage->get_event($event['id']))) {
       unset($ev['sequence']);
       return $this->update_event($event + $ev);
     }
 
     return false;
   }
 
   /**
    * Remove a single event
    *
    * @param array   Hash array with event properties:
    *      id: Event identifier
    * @param boolean Remove record(s) irreversible (mark as deleted otherwise)
    *
    * @return boolean True on success, False on error
    */
   public function remove_event($event, $force = true)
   {
     $success = false;
     $savemode = $event['_savemode'];
 
     if (($storage = $this->calendars[$event['calendar']]) && ($event = $storage->get_event($event['id']))) {
       $event['_savemode'] = $savemode;
       $savemode = 'all';
       $master = $event;
 
       $this->rc->session->remove('calendar_restore_event_data');
 
       // read master if deleting a recurring event
       if ($event['recurrence'] || $event['recurrence_id']) {
         $master = $event['recurrence_id'] ? $storage->get_event($event['recurrence_id']) : $event;
         $savemode = $event['_savemode'];
       }
 
       // removing an exception instance
       if ($event['recurrence_id']) {
         $i = $event['_instance'] - 1;
         if (!empty($master['recurrence']['EXCEPTIONS'][$i])) {
           unset($master['recurrence']['EXCEPTIONS'][$i]);
         }
       }
 
       switch ($savemode) {
         case 'current':
           $_SESSION['calendar_restore_event_data'] = $master;
 
           // removing the first instance => just move to next occurence
           if ($master['id'] == $event['id']) {
             $recurring = reset($storage->_get_recurring_events($event, $event['start'], null, $event['id'].'-1'));
 
             // no future instances found: delete the master event (bug #1677)
             if (!$recurring['start']) {
               $success = $storage->delete_event($master, $force);
               break;
             }
 
             $master['start'] = $recurring['start'];
             $master['end'] = $recurring['end'];
             if ($master['recurrence']['COUNT'])
               $master['recurrence']['COUNT']--;
           }
           else {  // add exception to master event
             $master['recurrence']['EXDATE'][] = $event['start'];
           }
           $success = $storage->update_event($master);
           break;
 
         case 'future':
           if ($master['id'] != $event['id']) {
             $_SESSION['calendar_restore_event_data'] = $master;
             
             // set until-date on master event
             $master['recurrence']['UNTIL'] = clone $event['start'];
             $master['recurrence']['UNTIL']->sub(new DateInterval('P1D'));
             unset($master['recurrence']['COUNT']);
 
             // if all future instances are deleted, remove recurrence rule entirely (bug #1677)
             if ($master['recurrence']['UNTIL']->format('Ymd') == $master['start']->format('Ymd'))
               $master['recurrence'] = array();
 
             $success = $storage->update_event($master);
             break;
           }
 
         default:  // 'all' is default
           $success = $storage->delete_event($master, $force);
           break;
       }
     }
 
     if ($success && $this->freebusy_trigger)
       $this->rc->output->command('plugin.ping_url', array('action' => 'calendar/push-freebusy', 'source' => $storage->id));
 
     return $success;
   }
 
   /**
    * Restore a single deleted event
    *
    * @param array Hash array with event properties:
    *      id: Event identifier
    * @return boolean True on success, False on error
    */
   public function restore_event($event)
   {
     if ($storage = $this->calendars[$event['calendar']]) {
       if (!empty($_SESSION['calendar_restore_event_data']))
         $success = $storage->update_event($_SESSION['calendar_restore_event_data']);
       else
         $success = $storage->restore_event($event);
       
       if ($success && $this->freebusy_trigger)
         $this->rc->output->command('plugin.ping_url', array('action' => 'calendar/push-freebusy', 'source' => $storage->id));
       
       return $success;
     }
 
     return false;
   }
 
   /**
    * Wrapper to update an event object depending on the given savemode
    */
   private function update_event($event)
   {
     if (!($storage = $this->calendars[$event['calendar']]))
       return false;
 
     // move event to another folder/calendar
     if ($event['_fromcalendar'] && $event['_fromcalendar'] != $event['calendar']) {
       if (!($fromcalendar = $this->calendars[$event['_fromcalendar']]))
         return false;
 
       if ($event['_savemode'] != 'new') {
         if (!$fromcalendar->storage->move($event['id'], $storage->get_realname()))
           return false;
 
         $fromcalendar = $storage;
       }
     }
     else
       $fromcalendar = $storage;
 
     $success = false;
     $savemode = 'all';
     $attachments = array();
     $old = $master = $fromcalendar->get_event($event['id']);
 
     if (!$old || !$old['start']) {
       rcube::raise_error(array(
         'code' => 600, 'type' => 'php',
         'file' => __FILE__, 'line' => __LINE__,
         'message' => "Failed to load event object to update: id=" . $event['id']),
         true, false);
       return false;
     }
 
     // delete existing attachment(s)
     if (!empty($event['deleted_attachments'])) {
       foreach ($event['deleted_attachments'] as $attachment) {
         if (!empty($old['attachments'])) {
           foreach ($old['attachments'] as $idx => $att) {
             if ($att['id'] == $attachment) {
               $old['attachments'][$idx]['_deleted'] = true;
             }
           }
         }
       }
       unset($event['deleted_attachments']);
     }
 
     // handle attachments to add
     if (!empty($event['attachments'])) {
       foreach ($event['attachments'] as $attachment) {
         // skip entries without content (could be existing ones)
         if (!$attachment['data'] && !$attachment['path'])
           continue;
 
         $attachments[] = array(
           'name' => $attachment['name'],
           'mimetype' => $attachment['mimetype'],
           'content' => $attachment['data'],
           'path' => $attachment['path'],
         );
       }
     }
 
     $event['attachments'] = array_merge((array)$old['attachments'], $attachments);
 
     // modify a recurring event, check submitted savemode to do the right things
     if ($old['recurrence'] || $old['recurrence_id']) {
       $master = $old['recurrence_id'] ? $fromcalendar->get_event($old['recurrence_id']) : $old;
       $savemode = $event['_savemode'];
     }
 
     // keep saved exceptions (not submitted by the client)
     if ($old['recurrence']['EXDATE'])
       $event['recurrence']['EXDATE'] = $old['recurrence']['EXDATE'];
     if ($old['recurrence']['EXCEPTIONS'])
       $event['recurrence']['EXCEPTIONS'] = $old['recurrence']['EXCEPTIONS'];
 
     switch ($savemode) {
       case 'new':
         // save submitted data as new (non-recurring) event
         $event['recurrence'] = array();
         $event['uid'] = $this->cal->generate_uid();
         
         // copy attachment data to new event
         foreach ((array)$event['attachments'] as $idx => $attachment) {
           if (!$attachment['data'])
             $attachment['data'] = $fromcalendar->get_attachment_body($attachment['id'], $event);
         }
         
         $success = $storage->insert_event($event);
         break;
 
       case 'future':
       case 'current':
         // recurring instances shall not store recurrence rules
         $event['recurrence'] = array();
         $event['thisandfuture'] = $savemode == 'future';
 
         // remove some internal properties which should not be saved
         unset($event['_savemode'], $event['_fromcalendar'], $event['_identity']);
 
         // save properties to a recurrence exception instance
         if ($old['recurrence_id']) {
             $i = $old['_instance'] - 1;
             if (!empty($master['recurrence']['EXCEPTIONS'][$i])) {
                 $master['recurrence']['EXCEPTIONS'][$i] = $event;
                 $success = $storage->update_event($master, $old['id']);
                 break;
             }
         }
 
         // save as new exception to master event
         $master['recurrence']['EXCEPTIONS'][] = $event;
         $success = $storage->update_event($master);
         break;
 
       default:  // 'all' is default
         $event['id'] = $master['id'];
         $event['uid'] = $master['uid'];
 
         // use start date from master but try to be smart on time or duration changes
         $old_start_date = $old['start']->format('Y-m-d');
         $old_start_time = $old['allday'] ? '' : $old['start']->format('H:i');
         $old_duration = $old['end']->format('U') - $old['start']->format('U');
         
         $new_start_date = $event['start']->format('Y-m-d');
         $new_start_time = $event['allday'] ? '' : $event['start']->format('H:i');
         $new_duration = $event['end']->format('U') - $event['start']->format('U');
         
         $diff = $old_start_date != $new_start_date || $old_start_time != $new_start_time || $old_duration != $new_duration;
         
         // shifted or resized
         if ($diff && ($old_start_date == $new_start_date || $old_duration == $new_duration)) {
           $event['start'] = $master['start']->add($old['start']->diff($event['start']));
           $event['end'] = clone $event['start'];
           $event['end']->add(new DateInterval('PT'.$new_duration.'S'));
           
           // remove fixed weekday, will be re-set to the new weekday in kolab_calendar::update_event()
           if ($old_start_date != $new_start_date) {
             if (strlen($event['recurrence']['BYDAY']) == 2)
               unset($event['recurrence']['BYDAY']);
             if ($old['recurrence']['BYMONTH'] == $old['start']->format('n'))
               unset($event['recurrence']['BYMONTH']);
           }
         }
         // dates did not change, use the ones from master
         else if ($event['start'] == $old['start'] && $event['end'] == $old['end']) {
           $event['start'] = $master['start'];
           $event['end'] = $master['end'];
         }
 
         // unset _dateonly flags in (cached) date objects
         unset($event['start']->_dateonly, $event['end']->_dateonly);
 
         $success = $storage->update_event($event);
         break;
     }
     
     if ($success && $this->freebusy_trigger)
       $this->rc->output->command('plugin.ping_url', array('action' => 'calendar/push-freebusy', 'source' => $storage->id));
     
     return $success;
   }
 
   /**
    * Get events from source.
    *
    * @param  integer Event's new start (unix timestamp)
    * @param  integer Event's new end (unix timestamp)
    * @param  string  Search query (optional)
    * @param  mixed   List of calendar IDs to load events from (either as array or comma-separated string)
    * @param  boolean Include virtual events (optional)
    * @param  integer Only list events modified since this time (unix timestamp)
    * @return array A list of event records
    */
   public function load_events($start, $end, $search = null, $calendars = null, $virtual = 1, $modifiedsince = null)
   {
     if ($calendars && is_string($calendars))
       $calendars = explode(',', $calendars);
 
     $query = array();
     if ($modifiedsince)
       $query[] = array('changed', '>=', $modifiedsince);
 
     $events = $categories = array();
     foreach (array_keys($this->calendars) as $cid) {
       if ($calendars && !in_array($cid, $calendars))
         continue;
 
       $events = array_merge($events, $this->calendars[$cid]->list_events($start, $end, $search, $virtual, $query));
       $categories += $this->calendars[$cid]->categories;
     }
 
     // add events from the address books birthday calendar
     if (in_array(self::BIRTHDAY_CALENDAR_ID, $calendars)) {
       $events = array_merge($events, $this->load_birthday_events($start, $end, $search, $modifiedsince));
     }
 
     // add new categories to user prefs
     $old_categories = $this->rc->config->get('calendar_categories', $this->default_categories);
     if ($newcats = array_diff(array_map('strtolower', array_keys($categories)), array_map('strtolower', array_keys($old_categories)))) {
       foreach ($newcats as $category)
         $old_categories[$category] = '';  // no color set yet
       $this->rc->user->save_prefs(array('calendar_categories' => $old_categories));
     }
 
     return $events;
   }
 
   /**
    * Get a list of pending alarms to be displayed to the user
    *
    * @see calendar_driver::pending_alarms()
    */
   public function pending_alarms($time, $calendars = null)
   {
     $interval = 300;
     $time -= $time % 60;
     
     $slot = $time;
     $slot -= $slot % $interval;
     
     $last = $time - max(60, $this->rc->config->get('refresh_interval', 0));
     $last -= $last % $interval;
     
     // only check for alerts once in 5 minutes
     if ($last == $slot)
       return array();
     
     if ($calendars && is_string($calendars))
       $calendars = explode(',', $calendars);
     
     $time = $slot + $interval;
     
     $events = array();
     $query = array(array('tags', '=', 'x-has-alarms'));
     foreach ($this->calendars as $cid => $calendar) {
       // skip calendars with alarms disabled
       if (!$calendar->alarms || ($calendars && !in_array($cid, $calendars)))
         continue;
 
       foreach ($calendar->list_events($time, $time + 86400 * 365, null, 1, $query) as $e) {
         // add to list if alarm is set
         $alarm = libcalendaring::get_next_alarm($e);
         if ($alarm && $alarm['time'] && $alarm['time'] <= $time && $alarm['action'] == 'DISPLAY') {
           $id = $e['id'];
           $events[$id] = $e;
           $events[$id]['notifyat'] = $alarm['time'];
         }
       }
     }
 
     // get alarm information stored in local database
     if (!empty($events)) {
       $event_ids = array_map(array($this->rc->db, 'quote'), array_keys($events));
       $result = $this->rc->db->query(sprintf(
           "SELECT * FROM kolab_alarms
            WHERE event_id IN (%s) AND user_id=?",
            join(',', $event_ids),
            $this->rc->db->now()
           ),
           $this->rc->user->ID
        );
 
       while ($result && ($e = $this->rc->db->fetch_assoc($result))) {
         $dbdata[$e['event_id']] = $e;
       }
     }
     
     $alarms = array();
     foreach ($events as $id => $e) {
       // skip dismissed
       if ($dbdata[$id]['dismissed'])
         continue;
       
       // snooze function may have shifted alarm time
       $notifyat = $dbdata[$id]['notifyat'] ? strtotime($dbdata[$id]['notifyat']) : $e['notifyat'];
       if ($notifyat <= $time)
         $alarms[] = $e;
     }
     
     return $alarms;
   }
 
   /**
    * Feedback after showing/sending an alarm notification
    *
    * @see calendar_driver::dismiss_alarm()
    */
   public function dismiss_alarm($event_id, $snooze = 0)
   {
     // delete old alarm entry
     $this->rc->db->query(
       "DELETE FROM kolab_alarms
        WHERE event_id=? AND user_id=?",
        $event_id,
        $this->rc->user->ID
     );
 
     // set new notifyat time or unset if not snoozed
     $notifyat = $snooze > 0 ? date('Y-m-d H:i:s', time() + $snooze) : null;
 
     $query = $this->rc->db->query(
       "INSERT INTO kolab_alarms
        (event_id, user_id, dismissed, notifyat)
        VALUES(?, ?, ?, ?)",
       $event_id,
       $this->rc->user->ID,
       $snooze > 0 ? 0 : 1,
       $notifyat
     );
     
     return $this->rc->db->affected_rows($query);
   }
 
   /**
    * List attachments from the given event
    */
   public function list_attachments($event)
   {
     if (!($storage = $this->calendars[$event['calendar']]))
       return false;
 
     $event = $storage->get_event($event['id']);
 
     return $event['attachments'];
   }
 
   /**
    * Get attachment properties
    */
   public function get_attachment($id, $event)
   {
     if (!($storage = $this->calendars[$event['calendar']]))
       return false;
 
     $event = $storage->get_event($event['id']);
 
     if ($event && !empty($event['attachments'])) {
       foreach ($event['attachments'] as $att) {
         if ($att['id'] == $id) {
           return $att;
         }
       }
     }
 
     return null;
   }
 
   /**
    * Get attachment body
    * @see calendar_driver::get_attachment_body()
    */
   public function get_attachment_body($id, $event)
   {
     if (!($cal = $this->calendars[$event['calendar']]))
       return false;
 
     return $cal->storage->get_attachment($event['id'], $id);
   }
 
   /**
    * List availabale categories
    * The default implementation reads them from config/user prefs
    */
   public function list_categories()
   {
     // FIXME: complete list with categories saved in config objects (KEP:12)
     return $this->rc->config->get('calendar_categories', $this->default_categories);
   }
 
   /**
    * Fetch free/busy information from a person within the given range
    */
   public function get_freebusy_list($email, $start, $end)
   {
     if (empty($email)/* || $end < time()*/)
       return false;
 
     // map vcalendar fbtypes to internal values
     $fbtypemap = array(
       'FREE' => calendar::FREEBUSY_FREE,
       'BUSY-TENTATIVE' => calendar::FREEBUSY_TENTATIVE,
       'X-OUT-OF-OFFICE' => calendar::FREEBUSY_OOF,
       'OOF' => calendar::FREEBUSY_OOF);
 
     // ask kolab server first
     try {
       $request_config = array(
         'store_body'       => true,
         'follow_redirects' => true,
       );
       $request  = libkolab::http_request(kolab_storage::get_freebusy_url($email), 'GET', $request_config);
       $response = $request->send();
 
       // authentication required
       if ($response->getStatus() == 401) {
         $request->setAuth($this->rc->user->get_username(), $this->rc->decrypt($_SESSION['password']));
         $response = $request->send();
       }
 
       if ($response->getStatus() == 200)
         $fbdata = $response->getBody();
 
       unset($request, $response);
     }
     catch (Exception $e) {
       PEAR::raiseError("Error fetching free/busy information: " . $e->getMessage());
     }
 
     // get free-busy url from contacts
     if (!$fbdata) {
       $fburl = null;
       foreach ((array)$this->rc->config->get('autocomplete_addressbooks', 'sql') as $book) {
         $abook = $this->rc->get_address_book($book);
 
         if ($result = $abook->search(array('email'), $email, true, true, true/*, 'freebusyurl'*/)) {
           while ($contact = $result->iterate()) {
             if ($fburl = $contact['freebusyurl']) {
               $fbdata = @file_get_contents($fburl);
               break;
             }
           }
         }
 
         if ($fbdata)
           break;
       }
     }
 
     // parse free-busy information using Horde classes
     if ($fbdata) {
       $ical = $this->cal->get_ical();
       $ical->import($fbdata);
       if ($fb = $ical->freebusy) {
         $result = array();
         foreach ($fb['periods'] as $tuple) {
           list($from, $to, $type) = $tuple;
           $result[] = array($from->format('U'), $to->format('U'), isset($fbtypemap[$type]) ? $fbtypemap[$type] : calendar::FREEBUSY_BUSY);
         }
 
         // we take 'dummy' free-busy lists as "unknown"
         if (empty($result) && !empty($fb['comment']) && stripos($fb['comment'], 'dummy'))
           return false;
 
         // set period from $start till the begin of the free-busy information as 'unknown'
         if ($fb['start'] && ($fbstart = $fb['start']->format('U')) && $start < $fbstart) {
           array_unshift($result, array($start, $fbstart, calendar::FREEBUSY_UNKNOWN));
         }
         // pad period till $end with status 'unknown'
         if ($fb['end'] && ($fbend = $fb['end']->format('U')) && $fbend < $end) {
           $result[] = array($fbend, $end, calendar::FREEBUSY_UNKNOWN);
         }
 
         return $result;
       }
     }
 
     return false;
   }
 
   /**
    * Handler to push folder triggers when sent from client.
    * Used to push free-busy changes asynchronously after updating an event
    */
   public function push_freebusy()
   {
     // make shure triggering completes
     set_time_limit(0);
     ignore_user_abort(true);
 
     $cal = get_input_value('source', RCUBE_INPUT_GPC);
     if (!($cal = $this->calendars[$cal]))
       return false;
 
     // trigger updates on folder
     $trigger = $cal->storage->trigger();
     if (is_object($trigger) && is_a($trigger, 'PEAR_Error')) {
       rcube::raise_error(array(
         'code' => 900, 'type' => 'php',
         'file' => __FILE__, 'line' => __LINE__,
         'message' => "Failed triggering folder. Error was " . $trigger->getMessage()),
         true, false);
     }
 
     exit;
   }
 
   /**
    * Callback function to produce driver-specific calendar create/edit form
    *
    * @param string Request action 'form-edit|form-new'
    * @param array  Calendar properties (e.g. id, color)
    * @param array  Edit form fields
    *
    * @return string HTML content of the form
    */
   public function calendar_form($action, $calendar, $formfields)
   {
     if ($calendar['id'] && ($cal = $this->calendars[$calendar['id']])) {
       $folder = $cal->get_realname(); // UTF7
       $color  = $cal->get_color();
     }
     else {
       $folder = '';
       $color  = '';
     }
 
     $hidden_fields[] = array('name' => 'oldname', 'value' => $folder);
 
     $storage = $this->rc->get_storage();
     $delim   = $storage->get_hierarchy_delimiter();
     $form   = array();
 
     if (strlen($folder)) {
       $path_imap = explode($delim, $folder);
       array_pop($path_imap);  // pop off name part
       $path_imap = implode($path_imap, $delim);
 
       $options = $storage->folder_info($folder);
     }
     else {
       $path_imap = '';
     }
 
     // General tab
     $form['props'] = array(
       'name' => $this->rc->gettext('properties'),
     );
 
     // Disable folder name input
     if (!empty($options) && ($options['norename'] || $options['protected'])) {
       $input_name = new html_hiddenfield(array('name' => 'name', 'id' => 'calendar-name'));
       $formfields['name']['value'] = kolab_storage::object_name($folder)
         . $input_name->show($folder);
     }
 
     // calendar name (default field)
     $form['props']['fieldsets']['location'] = array(
       'name'  => $this->rc->gettext('location'),
       'content' => array(
         'name' => $formfields['name']
       ),
     );
 
     if (!empty($options) && ($options['norename'] || $options['protected'])) {
       // prevent user from moving folder
       $hidden_fields[] = array('name' => 'parent', 'value' => $path_imap);
     }
     else {
       $select = kolab_storage::folder_selector('event', array('name' => 'parent'), $folder);
       $form['props']['fieldsets']['location']['content']['path'] = array(
         'label' => $this->cal->gettext('parentcalendar'),
         'value' => $select->show(strlen($folder) ? $path_imap : ''),
       );
     }
 
     // calendar color (default field)
     $form['props']['fieldsets']['settings'] = array(
       'name'  => $this->rc->gettext('settings'),
       'content' => array(
         'color' => $formfields['color'],
         'showalarms' => $formfields['showalarms'],
       ),
     );
     
     
     if ($action != 'form-new') {
       $form['sharing'] = array(
           'name'    => Q($this->cal->gettext('tabsharing')),
           'content' => html::tag('iframe', array(
             'src' => $this->cal->rc->url(array('_action' => 'calendar-acl', 'id' => $calendar['id'], 'framed' => 1)),
             'width' => '100%',
             'height' => 350,
             'border' => 0,
             'style' => 'border:0'),
         ''),
       );
     }
 
     $this->form_html = '';
     if (is_array($hidden_fields)) {
         foreach ($hidden_fields as $field) {
             $hiddenfield = new html_hiddenfield($field);
             $this->form_html .= $hiddenfield->show() . "\n";
         }
     }
 
     // Create form output
     foreach ($form as $tab) {
       if (!empty($tab['fieldsets']) && is_array($tab['fieldsets'])) {
         $content = '';
         foreach ($tab['fieldsets'] as $fieldset) {
           $subcontent = $this->get_form_part($fieldset);
           if ($subcontent) {
             $content .= html::tag('fieldset', null, html::tag('legend', null, Q($fieldset['name'])) . $subcontent) ."\n";
           }
         }
       }
       else {
         $content = $this->get_form_part($tab);
       }
 
       if ($content) {
         $this->form_html .= html::tag('fieldset', null, html::tag('legend', null, Q($tab['name'])) . $content) ."\n";
       }
     }
 
     // Parse form template for skin-dependent stuff
     $this->rc->output->add_handler('calendarform', array($this, 'calendar_form_html'));
     return $this->rc->output->parse('calendar.kolabform', false, false);
   }
 
   /**
    * Handler for template object
    */
   public function calendar_form_html()
   {
     return $this->form_html;
   }
 
   /**
    * Helper function used in calendar_form_content(). Creates a part of the form.
    */
   private function get_form_part($form)
   {
     $content = '';
 
     if (is_array($form['content']) && !empty($form['content'])) {
       $table = new html_table(array('cols' => 2));
       foreach ($form['content'] as $col => $colprop) {
         $colprop['id'] = '_'.$col;
         $label = !empty($colprop['label']) ? $colprop['label'] : rcube_label($col);
 
         $table->add('title', sprintf('<label for="%s">%s</label>', $colprop['id'], Q($label)));
         $table->add(null, $colprop['value']);
       }
       $content = $table->show();
     }
     else {
       $content = $form['content'];
     }
 
     return $content;
   }
 
 
   /**
    * Handler to render ACL form for a calendar folder
    */
   public function calendar_acl()
   {
     $this->rc->output->add_handler('folderacl', array($this, 'calendar_acl_form'));
     $this->rc->output->send('calendar.kolabacl');
   }
 
   /**
    * Handler for ACL form template object
    */
   public function calendar_acl_form()
   {
     $calid = get_input_value('_id', RCUBE_INPUT_GPC);
     if ($calid && ($cal = $this->calendars[$calid])) {
       $folder = $cal->get_realname(); // UTF7
       $color  = $cal->get_color();
     }
     else {
       $folder = '';
       $color  = '';
     }
 
     $storage = $this->rc->get_storage();
     $delim   = $storage->get_hierarchy_delimiter();
     $form   = array();
 
     if (strlen($folder)) {
       $path_imap = explode($delim, $folder);
       array_pop($path_imap);  // pop off name part
       $path_imap = implode($path_imap, $delim);
 
       $options = $storage->folder_info($folder);
 
       // Allow plugins to modify the form content (e.g. with ACL form)
       $plugin = $this->rc->plugins->exec_hook('calendar_form_kolab',
         array('form' => $form, 'options' => $options, 'name' => $folder));
     }
 
     if (!$plugin['form']['sharing']['content'])
         $plugin['form']['sharing']['content'] = html::div('hint', $this->cal->gettext('aclnorights'));
 
     return $plugin['form']['sharing']['content'];
   }
 
 
   /**
    * Return a (limited) list of color values to be used for calendar and category coloring
    *
    * @return mixed List for colors as hex values or false if no presets should be shown
    */
   public function get_color_values()
   {
       // selection from http://msdn.microsoft.com/en-us/library/aa358802%28v=VS.85%29.aspx
       return array('000000','006400','2F4F4F','800000','808000','008000',
         '008080','000080','800080','4B0082','191970','8B0000','008B8B',
         '00008B','8B008B','556B2F','8B4513','228B22','6B8E23','2E8B57',
         'B8860B','483D8B','A0522D','0000CD','A52A2A','00CED1','696969',
         '20B2AA','9400D3','B22222','C71585','3CB371','D2691E','DC143C',
         'DAA520','00FA9A','4682B4','7CFC00','9932CC','FF0000','FF4500',
         'FF8C00','FFA500','FFD700','FFFF00','9ACD32','32CD32','00FF00',
         '00FF7F','00FFFF','5F9EA0','00BFFF','0000FF','FF00FF','808080',
         '708090','CD853F','8A2BE2','778899','FF1493','48D1CC','1E90FF',
         '40E0D0','4169E1','6A5ACD','BDB76B','BA55D3','CD5C5C','ADFF2F',
         '66CDAA','FF6347','8FBC8B','DA70D6','BC8F8F','9370DB','DB7093',
         'FF7F50','6495ED','A9A9A9','F4A460','7B68EE','D2B48C','E9967A',
         'DEB887','FF69B4','FA8072','F08080','EE82EE','87CEEB','FFA07A',
         'F0E68C','DDA0DD','90EE90','7FFFD4','C0C0C0','87CEFA','B0C4DE',
         '98FB98','ADD8E6','B0E0E6','D8BFD8','EEE8AA','AFEEEE','D3D3D3',
         'FFDEAD');
   }
 
 
   private function resurces_ldap()
   {
     if (!isset($this->resources_dir)) {
       $this->resources_dir = new rcube_ldap($this->rc->config->get('calendar_resources_directory'), true);
     }
 
     return $this->resources_dir->ready ? $this->resources_dir : null;
   }
 
 
   /**
    * Fetch resource objects to be displayed for booking
    *
    * @param  string  Search query (optional)
    * @return array  List of resource records available for booking
    */
   public function load_resources($query = null, $num = 5000)
   {
     if (!($ldap = $this->resurces_ldap())) {
       return array();
     }
 
     // TODO: apply paging
     $ldap->set_pagesize($num);
 
     if (isset($query)) {
       $results = $ldap->search('*', $query, 0, true, true);
     }
     else {
       $results = $ldap->list_records();
     }
 
     if ($results instanceof ArrayAccess) {
       foreach ($results as $i => $rec) {
         $results[$i] = $this->decode_resource($rec);
       }
     }
 
     return $results;
   }
 
   /**
    * Return properties of a single resource
    *
    * @param mixed  UID string
    * @return array Resource object as hash array
    */
   public function get_resource($uid)
   {
     $rec = null;
 
     if ($ldap = $this->resurces_ldap()) {
       $rec = $ldap->get_record($uid);
 
       if (!empty($rec)) {
         $rec = $this->decode_resource($rec);
       }
     }
 
     return $rec;
   }
 
   /**
    *
    */
   public function get_resource_owner($dn)
   {
     $owner = null;
 
     if ($ldap = $this->resurces_ldap()) {
       $owner = $ldap->get_record(rcube_ldap::dn_encode($dn), true);
-      unset($owner['_raw_attrib'], $owner['_type'], $owner['ID']);
+      $owner['ID'] = rcube_ldap::dn_decode($owner['ID']);
+      unset($owner['_raw_attrib'], $owner['_type']);
     }
 
     return $owner;
   }
 
   /**
    * Extract JSON-serialized attributes
    */
   private function decode_resource($rec)
   {
     if (is_array($rec['attributes']) && $rec['attributes'][0]) {
       $attributes = array();
 
       foreach ($rec['attributes'] as $sattr) {
         $attr = @json_decode($sattr, true);
         $attributes += $attr;
       }
 
       $rec['attributes'] = $attributes;
     }
 
     // remove unused cruft
     unset($rec['_raw_attrib']);
 
     return $rec;
   }
 
 }