Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /var/www/webxxx/html/content/forum/showtopic.php on line 42

und das is genau unter der geänderten Zeile da steht dann

PHP-Code:
      while($row=mysql_fetch_array($result)) {
        if ($last_post_id < $row['post_id']){
        $last_post_id=$row['post_id'];
        }?>