Will this php script work for Wordpress 2.5?

one of the php scripts shows the most commented posts. It does not work though. Here is the script

<?php $result = $wpdb->get_results("SELECT comment_count,ID,post_title FROM $wpdb->posts ORDER BY comment_count DESC LIMIT 0 , 6");
foreach ($result as $topten) {
$postid = $topten->ID;
$title = $topten->post_title;
$commentcount = $topten->comment_count;
if ($commentcount != 0) { ?>
<li><a href="<?php echo get_permalink($postid); ?>" title="<?php echo $title ?>"><?php echo $title ?></a></li>
<?php } } ?>

Anything wrong with it? (I dont know any php)

Thank You

 

anyone? please