WPMU Featured Posts

Hi,

I just try to write a function to show top posts on the main blog for WPMU but it doesn’t work. What am I doing wrong? Here is the code.

<?php function featured_posts(){

global $wpdb;

$date = date('Y-m-d', strtotime('-1 months'));
$date2 = date('Y-m-d', strtotime('-1000 days'));
$days = (strtotime($date2) - strtotime($date)) / (60 * 60 * 24);
$duration = $days;

             $request = "SELECT ID, post_title, COUNT($wpdb->comments.comment_post_ID) AS 'comment_count' FROM $wpdb->posts, $wpdb->comments";
             $request .= " WHERE comment_approved = '1' AND $wpdb->posts.ID=$wpdb->comments.comment_post_ID AND post_status = 'publish'";
             if(!$show_pass_post) $request .= " AND post_password =''";
             if($duration !="") $request .= " AND DATE_SUB(CURDATE(),INTERVAL ".$duration." DAY) < post_date ";
             $request .= " GROUP BY $wpdb->comments.comment_post_ID ORDER BY comment_count DESC LIMIT $popularpostnumber";
             $posts = $wpdb->get_results($wpdb->prepare($request));
             if ($posts):
              echo '<ul>';
              foreach ($posts as $post):
               setup_postdata($post);
               $post_title = stripslashes($post->post_title);
               $comment_count = $post->comment_count;
               $permalink = get_permalink($post->ID);
               echo '<li><a href="' . $permalink . '" title="' . $post_title.'"><span class="entry">' . $post_title . ' <span class="details inline">(' . $comment_count.')</span></span></a></li>';
              endforeach;
              echo '</ul>';
             else:
              _e("Didn't find any featured posts");
             endif;

  }
?>

Code (markup):