You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to book a flight ticket from DCA to DFW. Could you help me in booking?

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

USER: My travelling dates are from May 23 - 25.

ASSISTANT: Can you please share your name?

USER: Kevin Anderson.

ASSISTANT: Is there any connection preference?

USER: I prefer for connecting flight.

ASSISTANT: Do you have any other specification?

USER: No.

ASSISTANT: Kevin Anderson, there are no flights available in your route.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.