add: if (!aFocusedWindow) return false;  
context: function isContentFrame(aFocusedWindow){  var focusedTop = Components.lookupMethod(aFocusedWindow, 'top')                             .call(aFocusedWindow);  return (focusedTop == window.content);}
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/24d5ffacf3a10988bf1c65a6174b43e5a4e92080/contentAreaUtils.js/clean/xpfe/communicator/resources/content/contentAreaUtils.js