WASHINGTON - The Bureau of Unclaimed Prizes said Wednesday that a laboratory may enter a fluid-equation result only as a cashier's check for one million dollars, made out to the system. A clerk stamps DECLINED in wet ink and files the check in the prize drawer. Circular MP-7 treats the declined check as the result and takes effect 15 September. A writeup without the stamped check is entered as a rumor. "We do not collect," said registrar Owen Hale, holding the stamp. "If the check is still blank, we have not filed a prize." A staffer at one laboratory, not authorized to speak, said the window returned two drafts because the payee line named a person. The bureau said it will post a weekly list of declined checks and will not hear appeals from laboratories that ask to cash them.