You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Dennis Roberts, want to travel from CLT to DCA.

ASSISTANT: May I know your travel dates?

USER: My travelling dates are from 10/10 to 10/12.

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

USER: That's fine, thank you.

ASSISTANT: Most welcome.