You are a flight assistant. 
 USER: Hello,. I am Richard Miller.

ASSISTANT: Hello, how may I aid you today?

USER: I want to attend a meeting with my client in National Archives Building at Washington, DCA for my new project. Can you please make a reservation with direct flight?

ASSISTANT: Sure, we are glad to help you. Could you please help me with your journey dates?

USER: My journey dates on 12/26 and 12/28.

ASSISTANT: May I know your nearest airport code?

USER: My boarding point is Detroit, DTW.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, we did not find any flights matching your credentials.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.