rem: var mailSession = Components.classes[mailSessionProgID].getService(Components.interfaces.nsIMsgMailSession); 
add: var mailSession = Components.classes[mailSessionContractID].getService(Components.interfaces.nsIMsgMailSession); 
context: function AddToSession(){    try {        var mailSession = Components.classes[mailSessionProgID].getService(Components.interfaces.nsIMsgMailSession);                mailSession.AddFolderListener(folderListener);	} catch (ex) {        dump("Error adding to session\n");    }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/6cc70ebd6c97bd0b2fe48c31f579e855387ced9d/msgMail3PaneWindow.js/buggy/mailnews/base/resources/content/msgMail3PaneWindow.js