About triggers

I do the following :

CREATE FUNCTION testf()
RETURNS bool
AS
'INSERT INTO TEST VALUES(\'Hi\');
...
...
SELECT true;'
LANGUAGE 'sql';

then :

CREATE TRIGGER syn_section_insert
AFTER INSERT ON SECTION FOR EACH ROW
EXECUTE PROCEDURE testf();

... and I obtain

ERROR: CreateTrigger: function testf () does not exist

but function exists...

What's the problem?

TIA.

Roberto

--
Roberto Moreda
Resp. Dpto. Informática Handem/San Luis
Tlf +34 981 779000
Fax +34 981 779022
Pol. Piadela Sur, Autovía A6 Sal.567
15300 Betanzos (A Coruña) - España