trigger question

Is there a way in PL/pgSQL to have a trigger look at the fields in a
%ROWTYPE variable to look for changes?

I'm looking to be able to log the fields that are different between old
and new in a trigger, but don't want to have to list each field (It
changes, occasionally, but it changes). I'd also like to add a
timestamp and flag field when I store the record in the log table.

Am I just SOL, or is there a way to do this? (7.2.1, if it matters).

Thanks,
LER
--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 972-414-9812 E-Mail: ler(at)lerctr(dot)org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749