how to disabled previous dates in date time picker using jquery other wise give me any other where disabled dates in date time picker

my code is this i want disabled previous dates:
 <script src="../js/jquery-1.4.1.min.js" type="text/javascript"></script>     <script src="../js/jquery.dynDateTime.min.js" type="text/javascript"></script>     <script src="../js/calendar-en.min.js" type="text/javascript"></script>     <link href="../css/calendar-blue.css" rel="stylesheet" type="text/css" />     <script type="text/javascript">         $(document).ready(function () {                        $("#<%=txtjourneydate.ClientID %>").dynDateTime({          & ...