if ($user_id) {
                    // Logged in, have they dismissed this message?
                    $query = "SELECT * FROM messages WHERE message_active = 1 AND message_id NOT IN (SELECT message_id FROM messages_viewed WHERE user_id = ".$this->db->real_escape_string($user_id).") ORDER BY message_id DESC LIMIT 1";
                } else {
                    // Guest, show it