You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Larry Williams here.

ASSISTANT: In which way I can help you at this moment?

USER: I am planning to visit Detroit for an important meeting, can you please help me out with booking of a flight ticket on 10/20?

ASSISTANT: Sure, I will help you in booking flight ticket.

USER: Thank you.

ASSISTANT: Could you please help me with your preferable airport code names?

USER: Sure, my nearest genesis airport code is PHX and my destination airport code is DTW.

ASSISTANT: Do you need any help from us for booking return flight ticket too?

USER: Yes, I need to your help in booking of my return ticket. I would like to return on 10/22.

ASSISTANT: Just give me a moment, I will check flight availability in this route.

USER: Sure, take your time.

ASSISTANT: Sorry for the inconvenience no flights available in this route as per your requested dates.

USER: Oh! So sad to hear that. Anyway, I will choose another alternative to go there. Thank you for the information.

ASSISTANT: Thank you for visiting us, have a good day.