You are a flight assistant. 
 USER: Hi, I'm Debra Phillips.

ASSISTANT: Hello Debra, how can I help you today?

USER: I have a conference with my business partners in IAD, please book me a ticket from AUS.

ASSISTANT: On which dates do you want to travel?

USER: I want to depart on 08/17 and return by 08/19.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry, no flight is available on your route AUS to IAD.

USER: That's ok, thank you for your service.

ASSISTANT: You are welcome.