You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Kathleen Allen, want to travel from DFW to DCA. Please help me.

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

USER: My trip dates are from 05/07 to 05/09.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

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

USER: It's ok, thank you.

ASSISTANT: Most welcome.