The Computer Doctor:

One day, Hank complained to a friend, "My elbow really hurts. I guess I
should see a doctor.  "His friend said, "Don't do that.  There is 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."

Hank 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 ten bucks. 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 device
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 store, located the computer, poured in the sample and
deposited the ten bucks.  The machine again made the usual noise, 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 rehab.
   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.