John is appearing on "Who Wants To Be A Millionaire" with Regis Philbin.

Regis, "John, you're up to $500,000 with one lifeline left: phone a friend. If you get it right, the next question is worth one million dollars. If you get it wrong, you drop back to $32,000. Are you ready?"

John, "Yes."

Regis, "Which of the following birds does not build its own nest? Is it A)robin, B) sparrow, C) cuckoo, or D) pigeon."

John, "I'd like to phone a friend. I'd like to call Mary."

Mary answers the phone: "Hello?"

Regis, "Hello Mary, it's Regis Philbin from Who Wants to be a Millionaire. I have your friend John here who needs your help to answer the one million dollar question. The next voice you hear will be John's..."

John, "Mary, which of the following birds does not build it's own nest? Is it A) robin, B) sparrow, C) cuckoo, or D) pigeon."

Mary, "Oh, John. That's simple. It's a cuckoo."

John: "Are you sure?"

Mary, "I'm sure."

Regis, " You heard Mary. Do you keep the $500,000 or play for the million?"

John, "I want to play; I'll go with C) cuckoo."

Regis, "Is that your final answer?"

John, "Yes."

Regis "Are you confident?"

John "Yes; I think Mary's pretty smart."

Regis, "You said C) cuckoo, and you're right! Congratulations, you have just won one million dollars!"

To celebrate, John flies Mary to New York. That night they go out on the town. As they're celebrating, John looks at Mary and asks her, "Tell me, how did you know that it was the cuckoo that does not build its own nest?"

"That's easy, everybody knows they live in clocks."