if (gTransactionMgr.numberOfRedoItems) document.getElementById('redo_command').removeAttribute('disabled'); else document.getElementById('redo_command').setAttribute('disabled', true); 
if (getTransactionMgr().canUndo()) doc.getElementById('undo_command').removeAttribute('disabled'); else doc.getElementById('undo_command').setAttribute('disabled', true);  if (getTransactionMgr().canRedo()) doc.getElementById('redo_command').removeAttribute('disabled'); else doc.getElementById('redo_command').setAttribute('disabled', true); } 
function updateUndoRedoMenu() {    if (gTransactionMgr.numberOfUndoItems)        document.getElementById('undo_command').removeAttribute('disabled');    else            document.getElementById('undo_command').setAttribute('disabled', true);    if (gTransactionMgr.numberOfRedoItems)        document.getElementById('redo_command').removeAttribute('disabled');    else            document.getElementById('redo_command').setAttribute('disabled', true);}
5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/5459/8f557b6620a7ffd0ae2bbc6b245ea6cb9b7a0fff/calendar.js/buggy/calendar/resources/content/calendar.js