You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Catherine White, want to travel from DTW to DCA. Please help me.

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

USER: My trip dates are from 04/01 to 04/03.

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

USER: It's ok, thank you.

ASSISTANT: Most welcome.