perche questo codice mi da solo JavaScript Essentials??

codice:
<html>
  <head>
 <script language="JavaScript">
<!--
function findPlugin(ext){
var thisExt, findExt;
for (var n=0; n<navigator.plugins.length;n++){
for (var m=0;m<navigator.plugins[n].length;m++){
thisExt=thisExt.substring(0,thisExt.indexOf(""));
if(finExt==ext)
return (true);
}}
return (false);
}
//-->
</script>
 </head>
 <body>
 <h3>
 JavaScript Essentials <script>findPlugin(mp3)</script>
 </h3>
 </body> 
</html>