You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Donald Walker, want to travel from IAH to AUS.

ASSISTANT: May I know your travelling dates?

USER: My travelling dates are from 11/09 to 11/11.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: That's fine, thank you.

ASSISTANT: Most welcome.