Can not get my Vaildation too work !!

Can not get my Vaildation too work !!

Am trying to vaildate this datepicker As a { required field } only. When submit is pressed.
 
Help needed with code to Vaildate this datepicker, cant get an error message from it.
 
 
 
 
 
 
<script src=" http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/jquery-ui.js"></script>
<script src="http://jzaefferer.github.com/jquery-validation/jquery.validate.js"></script>
  
<title>Reservations and booking form</title>
 



</head>
<body>
<script>
 $(document).ready(function()
 {
     $("#myForm").validate();
  
   });
 
  </script>
 
 
<script>
 $(document).ready(function()
  {
     $("#datepicker").datepicker();
  });
 
    </script>
 
       
  <script>
  $(function() {     
       $.datepicker.setDefaults({dateFormat: 'DD, d  MM yy', autoSize: true,
          minDate: -0, maxDate: '+1M +05D', showOn: 'button',
        buttonimage: '/contact/images/calender.gif', buttonimageOnly: true, });
  $('input[name="Your Check In Date Is"],input[name="Your Check Out Date Is"]').datepicker();
 
 }); 
 </script>
   
 
    <!-- <script>
  $("#myForm").validate();
  </script>-->
    
     <script type="text/javascript">
 
  $("#datepicker").validate({
   rules: {
     start_date: "required"
     },
     messages: {
     start_date: 'A Date is required'
     }
   });











































  $("#start_date").datepicker();
   
     </script> 
 
     <script type="text/javascript">
        $(function(){ 
            $("input[name='Your Check In Date Is']").datepicker();
            $("input[name='Your Check Out Date Is']").datepicker();
        });
     </script> 
  
    <!-- myForm -->
  
    <form id="myForm" method="post">
   
 <input class="start_date" id="start_date" name="start_date" size="30" type="text" />
   
  <form method="post" id="myForm">
   
    <label for="datepicker">Select Your Check In Date</label>
    <form method="post" id="myForm">
   
    <input name="Your Check In Date Is" maxlength="30"  class="text ui-widget-content ui-corner-all" />
   
   
    <label for="datepicker">Select Your Check Out Date</label>
    <input name="Your Check Out Date Is" maxlength="30" class="text ui-widget-content ui-corner-all" />
    <p>
 <input type="submit" id="submit" name="submit" value="Click To Comfirm Your Booking Details" />
   
</form>
  Any tips thanks andy