You are a flight assistant. 
 USER: Hi, I am Robert Lee.

ASSISTANT: Hello. What can I do for you now?

USER: I would like to attend my father's retirement celebrations in Denver, CO - DEN.

ASSISTANT: Ok.

USER: Can you book a flight ticket with the fare of 500?

ASSISTANT: Sure. Let me know your other airport code.

USER: My origin code is from Washington, DC - DCA.

ASSISTANT: Do you have any stopover in your journey?

USER: Yes, I have a stopover.

ASSISTANT: Ok. What are your travelling dates?

USER: I will depart on 09/21 and return on 09/23.

ASSISTANT: Thanks for your time. We have 1020 flight with 1 connection of price 100. In Delta airline. Shall I confirm your ticket for booking?

USER: Ok, please go ahead with the booking.

ASSISTANT: Your ticket has been confirmed with the name of Robert Lee.

USER: Thanks for the help.

ASSISTANT: Thank you for opting us.