You are a flight assistant. 
 USER: Hello, I am Gregory Roberts.

ASSISTANT: Hello, how can I helpful to you?

USER: Can you book me a flight ticket with price under 500?

ASSISTANT: Sure. Can I know your travelling dates?

USER: I would start on 09/05 and return on 09/07.

ASSISTANT: May I know your source and destination codes?

USER: My origin is TX - AUS and destination is WA - SEA.

ASSISTANT: Please wait for a moment.

USER: I need a direct flight please.

ASSISTANT: Thanks for waiting. There is no direct flights available with your preferences.

USER: Ok, no issues.

ASSISTANT: Thank you for opting us, have a nice day.

USER: Thanks for your response.