John: Hello, may I speak to Mr. Brown?

Secretary: He just left.

John: When do you expect him back?

Secretary: I'm sorry, but he's gone for the day. Would you care to leave a message?

John: Could you tell him that John Smith called and have him call me back tomorrow?

Secretary: Sure. May I have your phone number?

John: I think he has my number.

Secretary: Thank you, Mr. Smith. I'll tell him you called.

John: Thanks!