You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am John Hall.

ASSISTANT: Hall, how can I aid you today?

USER: I ma planning to attend a meeting at LAX. Can you please help me out to book a ticket from ATL?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: I would like to travel on 06/19 and return back on 06/21.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Sure.

ASSISTANT: Sorry Hall, there are no flights available on your requested dates.

USER: That's fine. Thank you for your service.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.