(defendant, farmer, executed four hedge-to-arrive (HTA) contracts with plaintiff for sale of grain, with each contract specifying price, type, and quantity of grain to be delivered, but none specifying a delivery date; rolling fees not mentioned in contracts, but defendant extended delivery periods multiple times and was charged each time; farmer ultimately did not deliver and contracts cancelled; farmer executed promissory notes agreeing to compensate plaintiff and then sued claiming that contracts were illegal off-exchange "futures contracts" and jury agreed; appellate court reversed - contracts were valid and enforceable "forward contracts").