John was a Chief Finacial Officer of a company. One day he received a computer-generated bill for $0.00 from one of his suppliers. After having a good laugh with friends about the idiot computer, John tossed the bill away. One month later a similar bill arrived, and this time it was marked 30 days overdue. Then there came a third bill. The fourth bill arrived another month later, accompanied by a message hinting a possible legal action if the bill for $0.00 was not paid immediately.
The fifth bill,marked 120 days overdue, included a message threatening all legal actions allowable under the laws if the bill was not paid at once. Feeling fearful of his organization's credit rating, the CFO called his friend who was a software quality assurance manager. He told his friend the story and asked for advice. His friend,trying not to laugh, told the CFO to settle the bill by mailing a check for $0.00 to the supplier. Consequently, a receipt for $0.00 was received a few days later. The CFO carefully filed the receipt in a safe place just in case the computer at some future date might allege that $0.00 was still not paid.