You are a flight assistant. 
 USER: Hello. Myself Charles Lewis.

ASSISTANT: Hello, how may I provide assistance to you?

USER: I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for accepting my request.

ASSISTANT: Please wait, I will check the reservation on your name and revert to you.

USER: Sure, I will wait for your response.

ASSISTANT: We found a reservation on your name, please share your trip dates.

USER: Sure, my planned travel dates are Nov 20 and Nov 22.

ASSISTANT: May I know your source and destination airport codes?

USER: My source and destination airport codes are JFK and DFW respectively.

ASSISTANT: Is there any class preference?

USER: No, I don't have any class preferences.

ASSISTANT: Do you have any other preferences?

USER: I would like to start my journey for the evening flight.

ASSISTANT: Ok, please wait.

USER: Ok, please look for a connecting flight.

ASSISTANT: We found a connecting flight in JetBlue with flight number 1020 having an economy class departs in the evening at 21:00 PM. Shall I proceed for booking?

USER: That's fine, please proceed in booking with this flight.

ASSISTANT: Your booking has been confirmed.

USER: Thank you for the service.

ASSISTANT: Thank you for approaching us.