Edit in JSFiddle

<input type="text" id="DOB" />

<p>Format options:<br />
	<select id="format">
		<option value="mm/dd/yy">Default - mm/dd/yy</option>
		<option value="yy-mm-dd">ISO 8601 - yy-mm-dd</option>
		<option value="d M, y">Short - d M, y</option>
		<option value="d MM, y">Medium - d MM, y</option>
		<option value="DD, d MM, yy">Full - DD, d MM, yy</option>
		<option value="'day' d 'of' MM 'in the year' yy">With text - 'day' d 'of' MM 'in the year' yy</option>
	</select>
</p>

$(document).ready(function () {
        $("#DOB").datepicker();
        $("#format").change(function () {
            $("#DOB").datepicker("option", "dateFormat", $(this).val());
        });
    });