You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: Can you please help me to book flight ticket from SEA to DCA?

ASSISTANT: Sure, please share me your travel dates.

USER: My trip dates are Dec 25 and Dec 27.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I prefer connecting flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: Dorothy Thomas here.

ASSISTANT: May I know your class preferences?

USER: I prefer business class to travel.

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

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for opting us.