You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I need a flight ticket booking from IAD to CLT, can you book a flight ticket?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you and my travel dates are Mar 9 and I will return back on Mar 11.

ASSISTANT: Can I know your name please?

USER: I am Brian White.

ASSISTANT: Can I know your specifications?

USER: I need a business class flight with a single drop off in my journey.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Sorry, there are no flights found.

USER: Not a problem with that one, I can prefer any other source. Thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: Welcome.