conflicting versions of query on the page.
the date picker adds jquery using this code:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1/jquery-ui.min.js"></script>
and further down, you add another jquery library:
<script type="text/Javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
jquery can only be added to the page once.