表格未序列化

I've got a form which is loaded through ajax, and posted using ajax. When try to send its data, nothing is added to post, here's a short version of code

<form id="userForm">
    <input type="text" name="username" />
    <button type="submit">Send</button>
</form>

Javascript:

(function($){
    $.fn.ajaxForm = function() {
        var $form = $(this);
        $form.submit(function(event){
            event.preventDefault();
            $.ajax({
                data: $form.serialize(),
                type: 'post',
            });
        });
    }
})(jQuery);

<script type="text/javascript">
    $("#userForm").ajaxForm();
</script>

Everything works fine, request is sent, but $form.serialize() is empty

And i only had to ask.....

I've also added disabling of fields to the form after submitting which was the reason for the serialize not working. Removed that and it's now fine, sorry for bothering.