begin
  if new.live_revision <> old.live_revision or
     new.publish_status <> old.publish_status
  then 

    insert into cr_item_publish_audit (
      item_id, old_revision, new_revision, old_status, new_status, publish_date
    ) values (
      new.item_id, old.live_revision, new.live_revision, 
      old.publish_status, new.publish_status,
      now()
    );

  end if;

  return new;

end;