Быстрое удаление в моде PM

<form method="post" action="message_list.php">
<div class="blocktable" style="margin-left: 152px;">

<script language="JavaScript" type="text/JavaScript">
 function ChekUncheck()
 {
          var i;
          for (i = 0; i < document.delet.elements.length; i++) {
               if(document.delet.chek.checked==true){
                  document.delet.elements[i].checked = true;
               } else{
                      document.delet.elements[i].checked = false;
                 }
          }
 }
</script>
<form method="post" action="message_list.php" name="delet">
<div class="blocktable" style="margin-left: 152px;">

                    <th >Delete</th>
                    <?php } else { ?>
                    <th class="tcr"><?php echo $lang_pms['Date'] ?></th>
                    <?php } ?>

                    <th ><input name="chek" type="checkbox" value="" onClick="ChekUncheck()"></th>
                    <?php } else { ?>
                    <th class="tcr"><?php echo $lang_pms['Date'] ?></th>
                    <?php } ?>