You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation which is with the name Nicholas Wilson, as my exam got postponed. Please help me out.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for your time, we found a reservation with your name. Kindly provide me your travel dates?

USER: My new reservation depart date is on 09/02 and return date is on 09/04.

ASSISTANT: May I know your airport codes?

USER: I want to fly from Phoenix, AZ- PHX to Chicago, IL- ORD.

ASSISTANT: We found a flight with your requirement, airline is JetBlue price is 100 with single connection. Shall I proceed with booking?

USER: Please go with booking.

ASSISTANT: Your booking is done.

USER: Thank you for your service.

ASSISTANT: Thanks for reaching us, have a good day.