Cast record as text

Hi,

I'm trying to build an audit system for several tables. My idea was to use
triggers and plpgsql to record changes made to "important tables" to a
special audit table. My problem is that I don't want to create a separate
audit log table for each table that is being monitored. What I would like
to do is just cast the data from NEW.* or OLD.* to text and insert it into
a text column. Is this possible? I'm using version 8.1.5.

Example:

CREATE TABLE t1 (foo text, bar text);
CREATE TABLE t2 (id int, col timestamp);
CREATE TABLE audit (id int, optype char, time timestamp, user text, target
text, oldvalues text, newvalues text);

CREATE FUNCTION audit() RETURNS TRIGGER AS $$
BEGIN

IF (TG_OP = 'INSERT') THEN

INSERT INTO audit(optype,time,user,target,newvalues) VALUES ('I ',
now(), current_user, TG_RELNAME, NEW.*::text);
RETURN NEW;

END IF;
RETURN NULL;
END;

$$ LANGUAGE plpgsql VOLATILE SECURITY DEFINER;

CREATE TRIGGER t1_audit AFTER INSERT OR UPDATE OR DELETE ON t1 FOR EACH
ROW EXECUTE PROCEDURE audit();
CREATE TRIGGER t2_audit AFTER INSERT OR UPDATE OR DELETE ON t2 FOR EACH
ROW EXECUTE PROCEDURE audit();

I guess the explanation is a bit vague, but I hope you got my point!

Regards

MP