You (answering): Hello?
Roger: Hello, this is Roger Hastings. May I please speak with Mrs Ellis?
You: I'm afraid she is not available at the moment. Would you like to leave a message?
Roger: Yes, my name is Roger Hastings, and my number is 12345678. Would you ask her to return my call?
You: I will give her the message when she returns.
Roger (answering): FedEx Worldwide Service, how may I help you?
You (calling): Yes, I would like to speak with Dorothy Ellis, please.
Roger: May I ask who is calling?
You: Emelda Forester.
Roger: Please hold for a moment; I will see if she is in. (Pause) Roger: I'm afraid she is not at her desk. May I take your name and number?
You: Yes, it's Emelda Forester at 138129380. Would you please ask her to return my call.
Roger: I will. Thank you and have a nice day.
If you have something more specific in mind, don't hesitate to ask.