You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what kind of service your looking for?

USER: I want to book a flight ticket to attend for a seminar in SFO. Can you please help me for booking from DCA?

ASSISTANT: Sure, please share me your travel dates.

USER: My travelling dates are on Aug 19 and 21.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a stopover.

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

USER: My name is Virginia Carter.

ASSISTANT: May I know your class preferences?

USER: I am fine with any class.

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

USER: Ok, thanks for your help.

ASSISTANT: Thank you for availing us.