You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Larry Green, want to travel from IAD to EWR. Please help me.

ASSISTANT: Sure, may I know your trip dates please?

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

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

USER: It's ok, thank you for your time.

ASSISTANT: Most welcome.