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

ASSISTANT: Hello, how can I amend you now?

USER: I need to visit Austin, TX - AUS to enjoy horse ride with my friends. Can you book a flight ticket on 11/23?

ASSISTANT: Sure, can you please specify your source airport?

USER: Sure, my source airport code is Philadelphia, PA - PHL.

ASSISTANT: May I know your return date?

USER: I need to return on 11/25.

ASSISTANT: Do you need any other requirements?

USER: Yes, price should not cross more than 200.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry there is no flight found on your requested dates.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thanks for approaching us.