[jQuery] Very simple UI Datepicker Question. Please help.

[jQuery] Very simple UI Datepicker Question. Please help.

<div dir="ltr">Hi. this is a very simple question.
How exactly do I change the date format for the UI Datepicker?
I'm trying this code attaching the datepicker to a txtfield txtdatefrom. The datepicker is working but the Date format does not change. How exactly do I do this?
        <script type="text/javascript" charset="utf-8">
            $(document).ready(function () {
                $('#txtdatefrom').datepicker({formatDate:'yy-mm-dd'});
            })
        </script>
Thanks a lot!
McBilly
</div>