You are a flight assistant. 
 USER: Hi. I am Kevin Perez.

ASSISTANT: Hello, how may I assist you today?

USER: I need to go to Washington DC - IAD to learn some software courses. Can you hold a ticket for me on 12/09?

ASSISTANT: Sure, may I know the source code and other journey date?

USER: Ok, I want to fly from Austin, TX - AUS. And I want to return on 12/11.

ASSISTANT: Sure. Please wait for a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. Unfortunately, there are no flights found on your given requirements.

USER: Ok, no problem. Thanks for your time.

ASSISTANT: Thank you.