pl/PgSQL, variable names in NEW

Hello,
is it possible to use variables as field names in the NEW record? Let's 
suppose I have a varchar attname containg the name of the field and I want 
to know a value that field of the NEW record.

Problem is that I get an error 'record "new" has no field "attname"'. Of 
course I want to use a value of NEW.author when col.attname = attname = 
'author'.

Is there a solution?

Example trigger function. It finds all columns in the table which are 
referenced in other tables and checks if the value of the column has 
changed. If yes, then invoke some other function. The problem is that the 
column name is in the 'col' record and is different during the loop and at 
each function call.

CREATE OR REPLACE FUNCTION replace_values() RETURNS trigger AS
$BODY$DECLARE    col record;    attname varchar;BEGIN    FOR col IN    SELECT DISTINCT pgaf.attname, pgaf.attnum
FROMpg_constraint, pg_attribute AS pgaf    WHERE pg_constraint.contype = 'f'    -- fkey    AND pg_constraint.confrelid
=TG_RELID    -- table oid    AND pgaf.attrelid = TG_RELID    AND pgaf.attnum = ANY(pg_constraint.confkey) LOOP
 
        attname := col.attname;        IF NEW.attname <> OLD.attname THEN            RAISE NOTICE '  value changed from
"%"to "%"', OLD.attname, NEW.attname;            -- INVOKE OTHER FUNCTION        END IF;    END LOOP;
 
END;
$BODY$  LANGUAGE 'plpgsql' VOLATILE;

-- 
Martin Edlman
Fortech Ltd.
57001 Litomysl, CZ