You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Carolyn Nelson. I want to book a flight ticket from DCA to IAD. Could you help me in booking?

ASSISTANT: Sure, could you please share your departure and arrival dates?

USER: My travelling dates are from 08/09 to 08/11.

ASSISTANT: Do you prefer a stopover in between your journey?

USER: Yes, I need a single connecting flight.

ASSISTANT: Ok, please wait for a moment, let me search a flight for you.

USER: Ok.

ASSISTANT: Sorry to say this, there are no flights available from your source.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for choosing our airlines, hope to serve you again.