function getTags()
 {
     $notice_tag = new Notice_tag();
     $query = 'select tag,count(tag) as weight from notice_tag join file_to_post on (notice_tag.notice_id=post_id) join notice on notice_id = notice.id where file_id=' . $notice_tag->escape($this->out->attachment->id) . ' group by tag order by weight desc';
     $notice_tag->query($query);
     return $notice_tag;
 }