The absent-minded professor banged his car into another at a crossroads. His was not damaged, but the other car was crushed.

"Call me up and tell me how much the repairs cost. I'll pay the bills," he told the other driver and started to pull away.
"What is your phone number?"
"It's in the phone book," the professor called back.
"But what's your name?"
"Oh, that's in the phone book, too."