Although I see you have jquery datepicker links and datepicker javascript page code (but have to enter date manually (mm/dd/yy).
Looking at your page source code, in the head section, you have:
<link type="text/css" href="../CSSFormBuilder/FD_Sharp__00Wide/Datepicker/css/jquery-ui-1.7.1.custom.css" rel="stylesheet" />
<script type="text/javascript" src="../CSSFormBuilder/FD_Sharp__00Wide/Datepicker/js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="../CSSFormBuilder/FD_Sharp__00Wide/Datepicker/js/jquery-ui-1.7.1.custom.min.js"></script>
The page can't find those jquery files. Check that they are there.