add: return null; 
context: function getPreviewTextForTask( toDoItem ){   var HolderBox = document.createElement( "vbox" );   var textString ;   if( toDoItem )   {      showTooltip = true; //needed to show the tooltip.               if (toDoItem.title)      {         var TitleHtml = document.createElement( "description" );	 textString = gCalendarBundle.getFormattedString("tooltipTitleElement", [toDoItem.title]);	 var TitleText = document.createTextNode( textString );         TitleHtml.appendChild( TitleText );         HolderBox.appendChild( TitleHtml );      }         var DateHtml = document.createElement( "description" );      var startDate = new Date( toDoItem.start.getTime() );      textString = gCalendarBundle.getFormattedString("tooltipTaskStart", 						   [gCalendarWindow.dateFormater.getFormatedDate( startDate )]);      var DateText = document.createTextNode( textString );      DateHtml.appendChild( DateText );      HolderBox.appendChild( DateHtml );         DateHtml = document.createElement( "description" );      var dueDate = new Date( toDoItem.due.getTime() );      textString = gCalendarBundle.getFormattedString("tooltipTaskEnd", 						      [gCalendarWindow.dateFormater.getFormatedDate( dueDate )]);      DateText = document.createTextNode( textString );      DateHtml.appendChild( DateText );      HolderBox.appendChild( DateHtml );         if (toDoItem.description)      {	var text = gCalendarBundle.getFormattedString("tooltipTaskDescription", [toDoItem.description]);		var lines = text.split("\n");	var nbmaxlines = 5 ;	var nblines = lines.length ;	if( nblines > nbmaxlines ) {	  nblines = nbmaxlines ;	  lines[ nblines - 1 ] = "..." ;	}		for (var i = 0; i < nblines; i++) {	  var DescriptionHtml = document.createElement("description");	  var DescriptionText = document.createTextNode(lines[i]);	  DescriptionHtml.appendChild(DescriptionText);	  HolderBox.appendChild(DescriptionHtml);	}      }            return ( HolderBox );   }    else   {      showTooltip = false; //Don't show the tooltip   }}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/30af29cd9cd52d46f2bfbdc3451bce0702c97368/calendar.js/buggy/calendar/resources/content/calendar.js