You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am planning to book a flight ticket to IAD from EWR, can you please help me out?

ASSISTANT: Sure, can I know your good name please?

USER: Sure, my name is Andrew Collins.

ASSISTANT:  When you are willing to travel?

USER: Sure, my trip dates are Sept 12 and Sept 14.

ASSISTANT:  Would you let us know if you have any other preferences?

USER: I prefer direct flight.

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

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for choosing us.