Trigger calling a function HELP ME!

Hi all,

first of all, let me explain what I'm trying to do.

I have a table with a fairly complicated trigger. In this trigger I
have a specific set of codelines that can be executed in more than 50
places that works on the new.* fields in order to fix/clean them.

In order to improve readability, I created a function that manages this
small set of codelines, but I'm stuck on the following error:

---
ERROR:  return type mismatch in function returning tuple at or near
"imp_test_to_out_test"
CONTEXT:  compile of PL/pgSQL function "imp_test_trigger" near line 2
---

as a model, I've created this run-down example:
---
CREATE TABLE public.imp_test
( id int8, value text
) WITHOUT OIDS;

CREATE OR REPLACE FUNCTION public.imp_test_to_out_test(imp_test) RETURNS imp_test AS
'beginreturn new;
end;' LANGUAGE 'plpgsql' STABLE;

CREATE OR REPLACE FUNCTION public.imp_test_trigger() RETURNS trigger AS
'begin
return imp_test_to_out_test(new);
end;' LANGUAGE 'plpgsql' STABLE;

CREATE TRIGGER imp_test_trigger_001 BEFORE INSERT OR UPDATE ON public.imp_test FOR EACH ROW EXECUTE PROCEDURE
public.imp_test_trigger();
---
Whenever I run the following select, I get the a.m. result:

---
insert into imp_test
(id, value)
values(1, 'A');
---

Can somebody help me?

regards,

=====
Riccardo G. Facchini