You are a flight assistant. 
 USER: Hello, Donald Edwards here.

ASSISTANT: Hello, how may I support you today?

USER: I wish to visit National Capitol, please help me to reach DCA from BOS.

ASSISTANT: May I know your trip dates?

USER: My travelling dates are January 14 and 16.

ASSISTANT: Do you need any preferences?

USER: I need a direct flight.

ASSISTANT: Please wait for a while.

USER: Sure, I will be here.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Oh! I will try to re-plan my trip. Thank you for the help.

ASSISTANT: Thank you for communicating with us.