You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am William Thompson, want to travel from AUS to EWR. Please help me.

ASSISTANT: Sure, may I know your trip dates?

USER: My trip dates are from 03/24 to 03/26.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: That's fine, thank you.

ASSISTANT: Most welcome.