You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. In which way I can aid you today?

USER: I would like to book a flight ticket from DCA to DFW, can you please help me to book a flight ticket?

ASSISTANT: Sure, I will help you with that. Can you please mention your preferable travel dates?

USER: Sure, my travelling dates are July 29 and July 31.

ASSISTANT: May I know your name for further process?

USER: My name is Stephen Hill.

ASSISTANT: Is there any additional preferences do you have?

USER: I need a direct flight.

ASSISTANT: Do you have any another specifications?

USER: No.

ASSISTANT: Ok, please wait a moment.

USER: Sure, take your own time.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.