rem: return GetSelectedMessages()[0]; 
add:      var selectedMessages = GetSelectedMessages(); if (selectedMessages) return selectedMessages[0]; else return null; 
context: function GetFirstSelectedMessage(){    try {        // Use this instead of gDBView.URIForFirstSelectedMessage, else it        // will return the currentIndex message instead of the highlighted        // message.        return GetSelectedMessages()[0];    }    catch (ex) {        return null;    }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/78e302b6714be6f05ea2a72a90860b6e2a41260a/msgMail3PaneWindow.js/clean/mailnews/base/resources/content/msgMail3PaneWindow.js