rem: return urlstr.slice(urlstr.lastIndexOf( "/" )+1); 
add:     var lastSlash = urlstr.slice(urlstr.lastIndexOf( "/" )+1); if (lastSlash) { var nameIndex = lastSlash.lastIndexOf( "filename=" ); if (nameIndex != -1) return (lastSlash.slice(nameIndex+9)); else return lastSlash; } return null; 
context: function extractFileNameFromUrl(urlstr){  if (!urlstr) return null;  return urlstr.slice(urlstr.lastIndexOf( "/" )+1);}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/c81ed03fda24bb6e36fe4a061c2bc52474ed256e/utilityOverlay.js/buggy/xpfe/communicator/resources/content/utilityOverlay.js