plpgsql loop question

hi,
i have a table called "zones": idzone, zone_name
and several tables called zonename_records (same structure), where
zonename is one of the zone_name in the "zones" table.
What i want to do is a function that union all of this tables
dinamically based on "zones" table, this is what i've done so far:

CREATE OR REPLACE FUNCTION get_all_records()
RETURNS SETOF record AS
$BODY$DECLARE
zones record;
recs record;
BEGIN
for zones in select lower(zone_name) as n from zones loop
for recs in select * from quote_ident(zones.n || '_records') loop
return next recs;
end loop;
end loop;
RETURN;
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE
COST 100;

but i get this error!

ERROR: wrong record type supplied in RETURN NEXT
CONTEXT: PL/pgSQL function "get_all_records" line 9 at RETURN NEXT

Andrea