Date time picker issue

Date time picker issue

Hi guys I have a text box which uses datetimepicker in jquery and I have checked all the links, it shows the date time in text field but when i click inside the box it wont open the calendar, can u please help me to figure out how i should get it runing in a way that when i click on a text field in opens the calendar?

thanks in advance

<!DOCTYPE html>
<
html>
 
<
head>
 
 
<
meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
 
 
<
title>jQuery UI Example Page</title>
 
 
<
link type="text/css" href="css/ui-lightness/jquery-ui-1.8.6.custom.css" rel="stylesheet" />
 

 
 
<
script type="text/javascript" src="js/jquery-1.4.2.min.js"></script>
 
 
<script type="text/javascript" src="js/jquery-ui-1.8.6.custom.min.js"></script>
 
 
<script type="text/javascript" src="js/timepicker.js">
</script>

<script type="text/javascript">  
 $(function() {  
    $(?#datetime?).datepicker({  
      duration: ?,  
       showTime: true,  
         constrainInput: false,  
      stepMinutes: 1,  
     stepHours: 1,  
       altTimeField: ",  
      time24h: false  
 });  
});  
</script> 

 
</head>
 
<body>
<input type="text" name="datetime" id="datetime" value="01.06.2009 00:00">
 
</body>
</html>