Trigger on VIEW not firing

Hi,

I have a problem with Triggers on VIEW:

suppose I have:

CREATE TABLE work (
id integer NOT NULL,
work TEXT,
worktype TEXT
);

CREATE VIEW worksub AS SELECT FROM work WHERE worktype='subordinate';

CREATE OR REPLACE FUNCTION wrk_view() RETURNS TRIGGER AS $wrk_tg$
BEGIN
RAISE NOTICE 'UPDATE VIEW FROM: % OPERATION: %',TG_TABLE_NAME,
TG_OP;
END;
$wrk_tg$ LANGUAGE plpgsql;

CREATE TRIGGER wrk_tg INSTEAD OF INSERT OR DELETE OR UPDATE ON worksub
FOR EACH ROW EXECUTE PROCEDURE wrk_view();

nothing appen when I insert row in work table.

Someone can help me?