Javascript Paging and submit data

<?php
    $arrCheckedCat = isset($_POST['cat']) ? $_POST['cat'] : array();
    $submittedPage = isset($_POST['p']) ? intval($_POST['p']) : 1;
    if ($submittedPage < 1) $submittedPage = 1;
  
    $submittedT = isset($_POST['t']) ? $_POST['t'] : '';
    ?>
<form name="frmF" action="" method="post">
  <input type="text" name="t" value="<?php echo $submittedT ?>" />
  <input type="hidden" name="p" value="<?php echo $submittedPage ?>" />
  Cat 1 <input value="1" type="checkbox" name="cat[]" <?php echo in_array(1, $arrCheckedCat) ? 'checked' : '' ?> />
  Cat 2 <input value="2" type="checkbox" name="cat[]" <?php echo in_array(2, $arrCheckedCat) ? 'checked' : '' ?> />
  Cat 3 <input value="3" type="checkbox" name="cat[]" <?php echo in_array(3, $arrCheckedCat) ? 'checked' : '' ?> />
    <input type=submit value="Submit">
</form>
  
  
<div id="pList" style="border:1px solid red">
  
    <a href="javascript:void(0);" onclick="gotoPage(1)">1</a>
    <a href="javascript:void(0);" onclick="gotoPage(2)">2</a>
    <a href="javascript:void(0);" onclick="gotoPage(3)">3</a><br />
    Paging
  
    <?php var_dump($_POST); ?>
</div>
      
<script type="text/javascript">
  function gotoPage(p) {
      var pagingT1Param = '<?php echo $_POST['t']; ?>';
      var pagingCatsParam = '<?php echo implode(",", $arrCheckedCat); ?>'.split(',');
    
    
      // Re-bind current submitted data
      var eins = document.getElementsByTagName('input');
      var i, nein = eins.length;
      for (i = 0; i < nein; i++) {
          ein = eins.item(i);
          if (ein.type == 'checkbox') {
              if (in_array(ein.value, pagingCatsParam)) ein.checked = true;
              else ein.checked = false;
          }
      }
    
      document.frmF.t.value = pagingT1Param;
      document.frmF.p.value = p;
      document.frmF.submit();
  }
 
  function in_array(e, a) {
      var i;
      for (i in a) {
          if (e == a[i]) return true;
      }
      return false;
  }
</script>