Repeat Visit

A young woman wasn't feeling well, and asked one her co-workers to
recommend a physician.

"I know a great one in the city, but he is very expensive. Five hundred
dollars for the first visit, and one hundred dollars for each one after
that."

The woman went to the doctor's office and, trying to save a little
money, cheerily announced.

"I'm back!"

Not fooled for a second, the doctor quickly examined her and said, "Very
good, just continue the treatment I prescribed on your last visit."