A test for being drunk
A police officer pulls over this guy who had been weaving in and out of the lanes.

He goes up to the guy's window and says, "Sir, I need you to blow into this breathalyzer tube."

The man says, "Sorry officer I can't do that. I am an asthmatic. If I do that I'll have a really bad asthma attack."

"Okay, fine. I need you to come down to the station to give a blood sample." "I can't do that either. I am a hemophiliac. If I do that, I'll bleed to death."

"Well, then we need a urine sample."

"I'm sorry officer I can't do that either. I am also a diabetic. If I do that I'll get really low blood sugar."

"Alright then I need you to come out here and walk this white line."

"I can't do that, officer."

"Why not?"

"Because I'm too drunk to do that!"

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.