You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Carolyn Young, want to travel from DFW to DCA.

ASSISTANT: Sure, may I know your travelling dates?

USER: My trip dates are from 12/04 to 12/06.

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

USER: It's ok, thank you.

ASSISTANT: My pleasure.