You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Raymond Thompson. I am planning to change an existing reservation, due to some urgent work at office.Can you please change my reservation?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure, take your own time.

ASSISTANT: I found your reservation, can you please help me with the new airport codes?

USER: My new airport codes are DCA to ATL.

ASSISTANT: Could you please provide the travel dates?

USER: I would like to travel on 12/23 and return on 12/25.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Ok.

ASSISTANT: Raymond, there is a flight available with price fare 100 and the connection is 1 with Hawaiian airline. Would you like me to proceed with the booking?

USER: Please, proceed the booking.

ASSISTANT: Your booking is confirmed with 1019 flight number.

USER: Thank you for your quick response and service.

ASSISTANT: You are welcome. Thank you for choosing our service.