listing Child page with thumbnail erroe

I created a custom page template and put these “child page listing with thumbnail” code footer <?php get_footer(); ?> not showing when I use this code.

<div id="section-container">
 <?php
 $pages = get_pages('child_of='.$post->ID.'&parent='.$post->ID.'&sort_column
  =menu_order&sort_order=asc');
   foreach($pages as $page)
  { ?>
    <div class="section-page">
  <div class="section-thumb"><a>ID) ?>" title="
   <?php echo $page->post_title ?>">
   <?php echo get_the_post_thumbnail($page->ID, array(150,100)); ?></a>
   </div>
   </div><!--section-text-->
    </div><!--section-page-->
   <?php } ?>
   </div>

here is codes
http://www.snipsave.com/user/behance