add:  if (!msgfolder) return; 
context: function SetTitleButton(uri,pickerID){	var picker = document.getElementById(pickerID);	var msgfolder = GetMsgFolderFromUri(uri);	var selectedValue = null;	if (msgfolder.isServer)		selectedValue = msgfolder.name;	else		selectedValue = msgfolder.name + " on " + msgfolder.server.prettyName; 	picker.setAttribute("value",selectedValue);	picker.setAttribute("uri",uri);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/54986cb7dffc4debb75ebf703327ae05c97f5877/msgFolderPickerOverlay.js/clean/mailnews/base/resources/content/msgFolderPickerOverlay.js