Gandolf989,
thanks for the responce. I got it to do what I wanted and with just one trigger and no other tables. I am using the following trigger

CREATE OR REPLACE TRIGGER AXIUM."RMVBALTRG"
BEFORE UPDATE OF
"LastPaymentAmount"
ON "PATIENT"
REFERENCING NEW AS NEW
FOR EACH ROW
BEGIN
IF (:NEW."LastPaymentAmount" > 0) THEN
:NEW."Office4" := ' ';
END IF;
END;
/

Now when someone makes a payment in the system thus updating the LastPaymentAmount field in the PATIENT table the trigger fires and applies the new payment as well as removes the BAL from the Office4 field. I am not sure what kind of trigger this is called, I thought it is a row level trigger, and I am not sure why it works and doesn't give me the mutating trigger error, maybe because it is manipulating the data before it applies it? at least it works though. That buys me time to figure out why it works.