Create Function issue

what is wrong with following Function?

CREATE OR REPLACE FUNCTION PartLookUp(partno varchar2) RETURN varchar2 AS
begin
 select part_id, replacement_part_id from parts where part_id=partno;

  if parts.replacement_part_id <> '' then

       call PartLookUp(parts.replacement_part_id);   end if;

  return parts.parts_id;

end Received on Thu Apr 11 2002 - 11:12:32 CDT