You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I would like to attend live music concert at Washington, can you please help me to reserve flight ticket from AUS to IAD?

ASSISTANT: Sure, please share me your trip dates.

USER: Sure, my planned travelling dates are Dec, 15 and Dec, 17 respectively.

ASSISTANT: Is there any time concern for you?

USER: Yes, I prefer to depart in afternoon.

ASSISTANT: Do you need direct flight or connecting flight?

USER: Yes, flight has to be with single connection.

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

USER: Sure, my name is Samantha Hall here.

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

USER: Ok, not an issue.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.