You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you now?

USER: I want to travel from ATL to DCA. Can you help me to book a flight ticket?

ASSISTANT: Sure, I am happy to help you. Please, share me your travel dates.

USER: I would like to fly in the flight on Sept 09 and Sept 11.

ASSISTANT: Let me know your connection limit.

USER: I want to have a connection of 1.

ASSISTANT: Do you have any class preference?

USER: No, but I want to depart in afternoon time and return in evening time.

ASSISTANT: Do you have any more specifications?

USER: Nothing.

ASSISTANT: May I know your name, please?

USER: I am Rachel Harris.

ASSISTANT: Sorry to say that, there are no flights available on that routes.

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

ASSISTANT: Thanks for opting us.