How to override the template for specific content type? this is mushy and it does not work on this theme

i created content type overlay

added this code to the page--overlay.tpl.php

<?php 
?>  
  <?php if (isset($page['content'])) : ?>
    <?php print render($page['content']); ?>
  <?php endif; ?> 

and it does not work

i want to only display content body for that content type
nothing worked i tried node--overlay.tpl.php, html--overlay........