You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am planning to fly in 03/10 to DEN, so can you help me to book a flight?

ASSISTANT: Sure, can I know your source code please?

USER: My preferred source code is DCA.

ASSISTANT: Could you please provide the return date?

USER: I would like to return on 03/12.

ASSISTANT: There is a flight in UA airline with price 200, can I book it?

USER: Proceed with booking under my name, Cynthia Adams.

ASSISTANT: Your ticket has been booked with flight number 1001.

USER: Thank you for your service.

ASSISTANT: You are welcome.