jQuery confirmation is not working

Question

Hello all,

I have used a jQuery confirmation, but it is not working for me. Here is my code:

<link rel="stylesheet" type="text/css" media="screen, projection" href="demo.css" />
<script type="text/javascript" src="jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="jconfirmaction.jquery.js"></script>

<script type="text/javascript">
  $(document).ready(function() {
    $('.ask-plain').click(function(e) {
      e.preventDefault();
      thisHref = $(this).attr('href');

      if (confirm('Are you sure')) {
        window.location = thisHref;
      }
    });

    $('.ask-custom').jConfirmAction({question : "Anda Yakin?", yesAnswer : "Ya", cancelAnswer : "Tidak"});
    $('.ask').jConfirmAction();
  });
</script>

<td  width="3%" align="left"><a href="cir_delete.jsp?cir_id=<%=rs.getString("cir_id")%>" class="ask" onClick="return popup(this, 'Report')"><IMG SRC="12.png" ALT="Delete" BORDER="0"></a></td>

Please advise me.