Urgently need help in javascript try...catch

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:

Code:

---

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

javascript cannot do this due to security issues, and thats a good thing.