You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Patrick Roberts.

ASSISTANT: How can I aid you today?

USER: I am planning to book a ticket from AUS to IAD. Can you please help em out to book a ticket for me?

ASSISTANT: On which dates do you want to travel?

USER: I would like to travel on 06/23 and return back on 06/25.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Patrick, no flight is available for you.

USER: That's fine. Thank you for your service.