TRENTON - A federal judge has put a temporary stop to New Jersey's plan to generate up to $80 million from unused gift cards, calling cards, and money orders. As part of the state budget, lawmakers passed a bill allowing the state to claim proceeds of gift cards if customers don't use them within two years. The state would claim inactive travelers' checks and money orders after three years. The judge's restraining order keeps the law from being enforced until a hearing can be held. The law was set to go into effect this week, but its constitutionality was challenged by several companies, including the American Express Travel Related Services Co., the New Jersey Retail Merchants Association, the New Jersey Food Council, and American Express Prepaid Card Management Corp. Gov. Christie will have to come up with $80 million elsewhere if the law is struck down. The administration is reviewing the ruling, Treasury spokesman Bill Quinn said. He said no estimate was available on how much money the state would miss out on while the court has the law on hold.