An invisible man is here to see you
Nurse: Doctor, there is an invisible man in your waiting room.

Doctor: Tell him I can't see him now. Next.

A large difference
A man went to the doctor's. The doctor came in and said,"Well, I've got some good news and some bad news. The bad news is that you have an inoperable brain tumor. The good news is our hospital has just been certified to do brain transplants and there has been an accident right out front and a young couple was killed and you can have whichever brain you'd like. The man's brain costs $100,000.00 and the woman's brain costs "$30,000.00." The patient could not help but ask, "Why such a large difference between the male and the female brain?" The doctor replied, "The female brain is used."