Urgently need help in javascript try...catch

[janice_2k]

Dear Gurus and members,
I am a javascript and programming newbie. How can I use javascript try ... catch to check for the existance of an exe file on user's computer? The basic idea of the script is as below:

function loadRecorder() {
   try
   (
	//load exe file located on user's computer, fixed path
	location.href = "file:///C:/Program Files/IEBAudioRecorder/AudioRecorder.exe";
   }
  
   catch
   {
          //display a message saying the program does not exist in user's computer
          //request user to download from the server
          location.href = "http://server:00/library/IEBAudioRecorder.exe";
   }
}

I don't know what var should I add after catch( ) and have no idea whether will this method work. I really appreciate if someone could complete the script above and guide me, if the script above doesn't work. Looking forward to some reply soon.

Thanks in advance,
Janice