...
...

 <div class="optional"> 
   <?php echo $form->labelTag('Nic/parent_id', 'Parent');?>
   <?php echo $html->selectTag('Nic/parent_id', $nics, $html->tagValue('Nic/parent_id'), array(), array(), true);?>
   <?php echo $html->tagErrorMsg('Nic/parent_id', 'Please select the Parent.') ?>
 </div>
...
...