title: Request.IsAjaxRequest returns false
body: <p>I have an MVC project in which I have a form with a submit button.  I have added a jquery client-side handler that intercepts the form submit event.  The javascript function calls the same MVC action that would have been called without the javascript.  </p>
  
  <pre><code> $("form[action ='/List/CreateItem']").submit(
              function() {
                  $.post($(this).attr("action"), $(this).serialize(), function(response) { $("#results").html(response); });
                  return false;
              }
              );
  </code></pre>
  
  <p>In the MVC action that is called, I test for Request.IsAjaxRequest to decide whether to return a view or a JSON result.  My problem is that Request.IsAjaxRequest is returning false, even though I know the call is being made from the jquery function.  (I know this because if I comment out the $.post line in the jquery function and just leave the return false line, nothing happens.  If I un-comment the line, the action gets executed - but it returns the view because IsAjaxRequest is false.)  </p>
  
  <p>Should this line cause Request.IsAjaxRequest to be true?</p>