how to add function after dragging image?

how to add function after dragging image?

Hi all,
i am new to jquery.
i just created a draggable image. Wow!

I am trying to create a jquery cardgame.
I can drag and drop a (thumbnail). card to the table. (took me some hours)

So after dragging i need to grab the name of the image, replace it for a bigger one and then an ajaxcall to my backend page to update some div's.

So my 2 questions are:
how do i grab the image name and how do i start the ajaxcall? (backend itself is not a problem for me)

My code untill now:

    <script type="text/javascript">
    $(function() {

        $(".draggable").draggable({ revert: 'invalid' });

        $("#droparea").droppable({
            activeClass: 'ui-state-hover',
            hoverClass: 'ui-state-active',
            drop: function(event, ui) {
                $(this).addClass('ui-state-highlight').find('p').html('Dropped!');
            }
        });

    });
    </script>

btw: after dropping my card, i dont get a message like Dropped, however i do not need this message, instead i want to do an ajaxcall then.

Thanks in advance for any help!