checkbox filter on comments

in order to use the checkbox ajax filter on comments i have added a new function hooking comment views:

function ajax_checklist_comment(&$a1, $op) { 
  if ($op == 'view') {
    $a1->comment = str_replace("%AJAX_CHECKLIST_NID%",$a1->nid."-".$a1->cid,$a1->comment);
  }
}