title: ajax timeout callback function
body: <p>Is there a way to run a function if jQuery's $.ajax function hits it's <code>timeout</code>?</p>
  
  <p>i.e.</p>
  
  <pre><code>$.ajax({
  ...
  ...
  ,timeout:1000(){do something if timeout)
  ...
  
  });
  </code></pre>