On Update (trigger hint)

Hi guys,

Please, give me some advices on how to do the
following:

I have the following table:

CREATE TABLE products (
id SERIAL,
description TEXT,
lastupdate date
);

Well, I would like to update the column "lastupdate"
with the value "now()" on every UPDATE executed on a
row of this table.

Do I have to create a function to do it? Can you help
me?

Regards,

Marcelo

______________________________________________________________________

Yahoo! Mail - O melhor e-mail do Brasil! Abra sua conta agora:
http://br.yahoo.com/info/mail.html