CREATE OR REPLACE FUNCTION copy_name() RETURNS TRIGGER AS
$BODY$
BEGIN
   UPDATE sayit_users SET screen_name=NEW.name WHERE user_id=NEW.user_id;
   RETURN new;
END;
$BODY$
language plpgsql;

CREATE TRIGGER update_name_trigger
	AFTER INSERT OR UPDATE OF name ON sayit_users
	FOR EACH ROW
		EXECUTE PROCEDURE copy_name();