plpgsql triggers question -> foo := NEW ?

Hi list,

I've searched the interactive docs and found this link:

http://www.postgresql.org/docs/7.3/interactive/plpgsql-trigger.html

There is no answer to the question below: How to set foo:= NEW or foo:=
OLD in plpgsql trigger function
(I have the same problem)

Any help is appreciated.

Thanks

Mihail Changalov