You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you please help me in booking my ticket from DFW to DCA?

ASSISTANT: Sure, I am gleeful to help you with that. Can you please share your preferable travel dates?

USER: Thank you and my preferable travelling dates are from 09/16 to 09/18.

ASSISTANT: May I know your name please?

USER: Myself Samantha Smith.

ASSISTANT: Would you like to travel in a direct flight or a  connecting flight?

USER: I need a single connecting flight.

ASSISTANT: Do you have any other specifications?

USER: My depart time should be in the evening.

ASSISTANT: Flight-1028 is available in American Airlines with single connection limit and the ticket fare is 200. Shall I proceed with booking?

USER: Please proceed with the booking.

ASSISTANT: Sorry for the inconvenience , there are no flights available in evening time.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for reaching us, have a great day.