trigger for granting permission to select a table as soon it is created

HI
I am using postgersql and i am newbie,
i want to grant select permission to a group on table that will be created by me in future.
so i used trigger and a function
CREATE FUNCTION permitselect () RETURNS opaque AS 'DECLARE BEGIN GRANT SELECT ON NEW to GROUP wp; RETURN NEW; END; ' LANGUAGE 'plpgsql';
and trigger as
CREATE TRIGGER permit_select
AFTER INSERT OR UPDATE
ON queries FOR EACH ROW
EXECUTE PROCEDURE permitselect();

queries is table where meta data of tables created by me is stored. so new table created will be listed in table queries.

but on execution it gives error:
NEW used in non-rule query
Error occurred while executing PL/pgSQL function permit
Can any body help me how i can write a trigger for granting permission to select a table as soon it is created
thanks in advance
santosh dwivedi

__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com