rem: var mailSession = Components.classes[mailSessionProgID].getService(); if(mailSession) { mailSession = mailSession.QueryInterface(Components.interfaces.nsIMsgMailSession); if(mailSession) { mailSession.RemoveFolderListener(folderListener); } } 
context: function OnUnloadMessenger(){	dump("\nOnUnload from XUL\nClean up ...\n");	var mailSession = Components.classes[mailSessionProgID].getService();	if(mailSession)	{		mailSession = mailSession.QueryInterface(Components.interfaces.nsIMsgMailSession);		if(mailSession)		{			mailSession.RemoveFolderListener(folderListener);		}	}		OnMailWindowUnload();}
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/f8f0cb1c520d9c247917377952dfe8b507af2aff/msgMail3PaneWindow.js/buggy/mailnews/base/resources/content/msgMail3PaneWindow.js