In 1996, Troy Blackford was gambling at Prairie Meadows Casino when he destroyed a slot machine. After pleading guilty to criminal mischief, Blackford was banned from the casino. In 1998, Blackford was found in the casino, escorted out, and charged with trespass. In 2006, he gambled at the casino again and won $9,387. When Blackford went to collect his winnings, casino employees learned who he was and refused to pay. He sued for breach of contract, contending that he and the casino had an enforceable contract because he had accepted its offer to gamble. The casino argued that it had not made an offer and in fact had banned Blackford from the premises. The trial court held in favor of the casino. The appellate court reversed and ordered a new trial. The casino appealed to the Iowa high court for review. Did the casino make a valid offer to Blackford to gamble and thus create an enforceable contract between them? Explain your answer. [Blackford v. Prairie Meadows Racetrack and Casino, 778 N.W.2d 184 (Sup.Ct. Iowa 2010)]