One day, a man complained to his friend, "My elbow really hurts, guess I should see a doctor." His friend said, "Don't do that. There's a computer at the drug store that can diagnose anything quicker and cheaper than a doctor. Simply put in a sample of your urine, and the computer will diagnose your problem and tell you what you can do about it. And it only costs $10.00."
The guy figured he had nothing to lose, so he filled a jar with a urine sample and went to the drug store. Finding the computer, he poured in the sample and deposited the $10.00.
The computer started making some noise and various lights started flashing. After a brief pause, out popped a small slip of paper which read: "You have tennis elbow. Soak your arm in warm water, avoid heavy labor. It will be better in two weeks."
That evening while thinking how amazing this new technology was and how it would change medical science forever, he began to wonder if this computer could be fooled. He decided to give it a try.
He mixed together some tap water, a stool sample from his dog, and urine samples from his wife and daughter. To top it off, he masturbated into the concoction. He went back to the drug store, located the computer, poured in the sample and deposited the $10.00.
The machine again made the usual noises, flashed lights, and printed out the following analysis:
Your tap water is too hard. Get a water softener. Your dog has ringworm. Bathe him with anti-fungal shampoo. Your daughter is using cocaine. Put her in a rehabilitation clinic. Your wife is pregnant... twin girls. They aren't yours. Get a lawyer. And.... if you don't stop jerking off, your elbow will never get better.