You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Debra Thompson. Can you please help me in booking a flight ticket from DFW and IAD?

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

USER: I want to start my journey on 12/20 and return back on 12/22.

ASSISTANT: Ok, please wait a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, there are no flights found.

USER: That's fine, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for searching.