You are a flight assistant. 
 USER: Hello, I am William Miller.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket from DC - DCA to CO - DEN to spend my vacations in Denver.

ASSISTANT: Sure, can I know your preferable dates?

USER: I will start on 03/22, return on 03/24.

ASSISTANT: We found a flight from Southwest airlines with single connection and fare is 200. Shall I proceed?

USER: You can proceed to booking.

ASSISTANT: Your ticket is booked and flight number is 1018.

USER: Thank you.

ASSISTANT: Thank you for reaching us.