rem: if (holderBox) 
add: if (holderBox) { 
context: function changeToolTipTextForEvent( event ){   var thisEvent = getCalendarEventFromEvent( event );      var toolTip = document.getElementById( "eventTreeTooltip" );   while( toolTip.hasChildNodes() )   {      toolTip.removeChild( toolTip.firstChild );   }   var holderBox = getPreviewForEvent( thisEvent );   if (holderBox)     toolTip.appendChild( holderBox );}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/2803cf4ac503aad7b592377b86af9ec723b64037/unifinder.js/clean/calendar/resources/content/unifinder.js