You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Donna Mitchell.

ASSISTANT: How shall I address you for the day?

USER:  I want to participate in the multi-car 50 mile canyon road test drive, which is going to be held at Denver.

ASSISTANT: Ok.

USER: Can you help me out in booking a ticket?

ASSISTANT: Sure, help me with your airport codes.

USER: I need to leave from my nearest airport DCA to reach DEN.

ASSISTANT: On which dates you want to travel?

USER: I want to travel on 07/28, and need to catch return flight on 07/30.

ASSISTANT: Please hold on.

USER: Sure.

ASSISTANT: There is a flight with 1 connection of price 100 in Delta airline that matches with your information. Can I book a ticket for you?

USER: Yes, proceed with booking.

ASSISTANT: Ok, confirmation was done.

USER: Than you for the help.

ASSISTANT: Thank you. Have a nice journey.