rem: if (!frame || !("contentWindow" in frame)) 
add: var window = getContentWindow(frame); if (!window) 
context: function checkScroll(frame){    if (!frame || !("contentWindow" in frame))        return false;    var w = frame.contentWindow;    return ((w.document.height - (w.innerHeight + w.pageYOffset)) < 160);}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/bed39e8f3c219944b1ef2a4dc9163acf12791b06/static.js/buggy/extensions/irc/xul/content/static.js