Hello? This is Steven. I'd like to speak to Mr. Brown, please.
I'm afraid he is not in at the moment.
Then what time do you think he will be in?
I suppose he won't come back until 6 p. m. By the way, do you want to call later, or would you like to leave a message?
I'd like to leave a message. Please ask him to give me a call as soon as he returns. He has my number.
Okay, I'll do that.
Thank you. Bye-bye!
You're welcome, bye!