JavaScript Error Handling

Error trapping with JavaScript only works for newer generation browsers. However, older browser generally ignore window.onerror code, so it is worth putting in. There are two ways to do this:

Handling Errors via the window.onerror DHTML Event

function reportError(msg,url,line) {
  // do what you want with the message (msg), url (url) 
  // and line number (line) here
  return true;
}

window.onerror = reportError;

Handling Errors via ECMAScript 2.0 Exception Handling

  try {
    // code that may cause an error
  }
  catch (exception) {
    alert(err.number + ' ' + err.description);
  }
  finally {
     // code that is always executed
  }