We sometimes have guests pay with an In-House Gift Certificate and not use the full amount - say the GC is for $500 but they only use $400. They request a "new" GC with the balance of $100 showing. Even after posting the payment of $400, when we print the same Gift Certificate only the original Value of $500 shows. We would like to ADD the field (Total - Amount used), and call it Balance Available... to a printed Gift Certificate.