Calling stored procedures in table constraint checks

I guess I need an example how I can pass an entire row to a stored
procedure called in a table constraint check.

Is this possible at all?

-- 
Florian Weimer                       Weimer@CERT.Uni-Stuttgart.DE
University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT                          fax +49-711-685-5898