You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to book a ticket from DCA to CLT. Could you book a ticket?

ASSISTANT: Sure, may I know your good name please?

USER: My name is Dorothy Smith.

ASSISTANT: When do you want to travel?

USER: Depart date is Dec, 29 and return by Dec, 31.

ASSISTANT: Please share your connection limit.

USER: I would prefer connecting flight.

ASSISTANT: Are there any other specifications?

USER: I would like to depart in the evening.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Thank you.

ASSISTANT: Thank you for opting us.