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!