A diner in a New York restaurant complains to a waiter that the room is too warm and he asks the waiter to turn on the air conditioning. The waiter disappears to the back of the restaurant. A few minutes later the same diner complains that the restaurant is too cold and asks the same waiter to turn off the air conditioning. The waiter disappears to the back of the restaurant. This happens again and again. Another diner, observing this sequence of events, calls the waiter over and says, "I'd just like to say that I think its really bad how that man is messing you about over the air conditioning." The waiter replies, "Actually sir, I'm messing him about. You see, there is no air conditioning."