Wordpress: do only if page has ancestor

gistfile1.phtml

<?php
function has_ancestor($pid)
{
  global $post;
  $ancestors = get_post_ancestors($post->$pid);
  $root = count($ancestors);
  if ( $root < 1) { return false; } // set to false in case of no ancestors
  $parent = $ancestors[$root];
  if(is_page() && (is_page($pid) || $post->post_parent == $pid || in_array($pid, $ancestors)))
  {
    return true;
  }
  else
  {
    return false;
  }
};

$id = get_the_ID();

if  (has_ancestor($id )) {
// do stuff when true, eg. showing a breadcrumb
}

?>