Triggers in postgres

Hi,

I have a product table with a column barcode.  After a product has been
deleted, I want to create a trigger to delete references to that product
in other tables.  I've got the following trigger

CREATE TRIGGER
AFTER DELETE
ON TABLE product
FOR EACH ROW

Now, what I would ideally like to do is issue a simple sql delete command,
but I think I actually have to define a function (is this true?).  Say I
do, then the rest of my trigger would look like

EXECUTE PROCEDURE someProc();

Now I need to pass somProc the barcode of the product I've just deleted.
How do I do this?

Thanks

Rob

-- 
He who dies with the most toys ...

					... still dies