JQuery .ajax() success always firing (even when server returns error code)

I have a form that is being serialized by JQuery and posted via .ajax() to a url.

The problem is that the 'success:' function is always called, regardless of whether the server returns an error code or not.

In fact, success fires even before the server has responded (I have put a breakpoint on the server method that services the request - success fires even before this method is completed). If the server returns an error code (e.g. Status code 500) JQuery calls开发者_StackOverflow社区 BOTH success and error events!

Any ideas what's going on? Here's my jquery code:

$("#a-dialog").dialog({
    autoOpen: false,
    height: 300,
    width: 400,
    modal: true,
    buttons: {
    "Submit": function() {
                $.ajax({
                  type: 'POST',
                  url: theURL,
                  data: $("#a-dialog-form").serialize(),
                  success: alert('ok!') // THIS IS ALWAYS CALLED (IMMEDIATELY)
                });
        },
    },
});

UPDATE:

This was a stupid error on my part! Thanks to blue112 for quickly pointing it out :)

That's normal, you must pass it as a callback, eg

            $.ajax({
              type: 'POST',
              url: theURL,
              data: $("#a-dialog-form").serialize(),
              success: function(){alert('ok!');} // The function will be called upon success.
            });

You need to provide success with a pointer to a function, or, as commonly used, by passing the function definition.

What you have to do is have something like this:

 "Submit": function() {
                $.ajax({
                  type: 'POST',
                  url: theURL,
                  data: $("#a-dialog-form").serialize(),
                  success: function (data) {
                          alert('ok!') // THIS IS ALWAYS CALLED (IMMEDIATELY)
                  }
                });
        },
    },

What's happening in your case is that the alert is called right away so you will see the alert message even if the ajax request didn't get fired at all.