You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you at this moment?

USER: I am going to attend my cousin's marriage party at IAD, can you please help me in booking a flight ticket from DCA?

ASSISTANT: Sure, please share your planned travel dates.

USER: My travelling dates are 23rd June and 25th.

ASSISTANT: May I know your connection limit?

USER: I am comfortable in single connecting flight.

ASSISTANT: Ok, do you prefer a economy class or business class?

USER: I am flexible in any class.

ASSISTANT: Sure, may I know your name to proceed further?

USER: Myself Dorothy King.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights available on your journey dates.

USER: Not an issue, thank you for your information.

ASSISTANT: Thank you, we hope to serve you better next time.