jQuery 1.8.2 datepicker - two fields

jQuery 1.8.2 datepicker - two fields

I'm trying to implement the datepicker and I have two fields on my form: Birthdate & Lived here since?
 
In my header I have:
  1.  <script type="text/javascript" src="javascript/jquery/jquery-1.4.2.js"></script>
     <script type="text/javascript" src="javascript/jquery/ui/jquery.ui.core.js"></script>
     <script type="text/javascript" src="javascript/jquery/ui/jquery.ui.widget.js"></script>
     <script type="text/javascript" src="javascript/jquery/ui/jquery.ui.datepicker.js"></script>
     <link type="text/css" href="javascript/jquery/themes/ui-lightness/jquery.ui.datepicker.css" rel="stylesheet" />
     <script type="text/javascript">
     $(function() {
      $('#datepicker').datepicker({
       changeMonth: true,
       changeYear: true
      });
     });
     </script>











The html looks like this:

  1.   <tr>
        <td>Date of Birth MM/DD/YYYY<br>(Restrict kids from some areas)</td>
        <td><input type='text' id='datepicker' name='dob' maxlength='12' /></td>
      </tr>
      <tr>
        <td>Lived here since?</td>
        <td><input type='text' id='datepicker' name='since' maxlength='12' /></td>
      </tr> 






 

When I click on the 1st date field (birthday) it mostly works... I say mostly because it doesn't appear to be pulling in that css as the widget is pretty spread out and has no borders etc.
 
When I click on the 2nd date field (here since?), absolutely nothing happens.
 
Surely this supports multiple date fields on the same form so what am I doing wrong?
 
Thanks,
 
Pete