What's wrong with this page?

What's wrong with this page?

I wrote this small page and for some reason when I cilck on the submit nothing happens (checked on firebug, no submit is happening)

<html>

    <head>
        <script type="text/javascript" src="jquery-1.4.2.min.js"></script>
        <script type="text/javascript">

            $('form#login').submit(function() {
                $.ajax({
                    type: 'POST',
                    url: 'http://my.site/login.php',
                    data: this.html(data),
                    success: success,
                    dataType: dataType
                })

            });






        </script>
    </head>
    <body>
        <form action="#" id="login">
            <input type="textbox" id="UserName" value="user">
            <input type="textbox" id="Password" value="password">
            <input type="submit" value="submit">
        </form>
    </body>



</html>