title: Tracking visitor JS errors?
body: <p>Is it possible to track JS errors that a visitor encounters? Obviously we do our own testing, but from time to time a visitor will be running a certain browser version, or have a particular plugin, at it'll cause a JS error. Likewise sometimes an error in the JS gets to production unnoticed.</p>
  
  <p>It would be extremely useful if we could somehow capture these events, and ajax a script on our server with details of the error so that we could attempt to fix the issue.</p>
  
  <p><strong>UPDATE:</strong>
  Thanks for the feedback. Typically after posting I managed to find:<br>
  <a href="https://stackoverflow.com/questions/119432/logging-javascript-errors-on-server">Logging Clientside JavaScript Errors on Server</a> <br>
  Which had the stuff on window.onerror and also some interesting things about JQuery and a FireFox onerror bug that still hasn't been fixed for years...</p>