Set jQuery UI DatePicker Date Format in jQuery

How to set Date Format in jQuery UI DatePicker (Calendar) Example in ASP.Net

format: 'dd/MM/YYYY' IS NOT WORKING

I USE dateFormat: 'dd-mm-yy'

    <script type="text/javascript">
        $(function () {
            $("[id*=txtBharatKoshDated]").datepicker({
                showOn: 'button',
                buttonImageOnly: true,
                format: 'dd/MM/YYYY',
                buttonImage: '../../images/calendar.png'
            });
        });
    </script>