<select name="shipmethod" class='shipmethod'>
<option value='FIRST_OVERNIGHT'>FIRST OVERNIGHT : $62.38</option>
<option value='PRIORITY_OVERNIGHT'>PRIORITY OVERNIGHT : $47.45</option>
<option value='STANDARD_OVERNIGHT'>STANDARD OVERNIGHT : $28.42</option>
<option value='FEDEX_2_DAY'>FEDEX 2 DAY : $15.37</option>
<option value='FEDEX_EXPRESS_SAVER'>FEDEX EXPRESS SAVER : $13.76</option>
<option value='FEDEX_GROUND'>FEDEX GROUND : $6.9</option>
</select>


<script type="text/javascript">
    $(document).ready(function()
    {
        $(".shipmethod").change(
        function()
        {
            $.get("ajax.php", { shipping : $(this).val()  });
                    window.location = "cart.php";
        }
        );
    });
</script>

if(isset($_GET['shipping']))
{
   $data = mysql_real_escape_string($_GET['shipping']);
   $_SESSION['shipping'] = $data;
   header("Location: cart.php");
}