You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you at present?

USER: I am Matthew Johnson. I need to change my existing reservation, as my exam scheduled has been postponed. Please help me in changing?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, we found a reservation on your name. Please provide your new reservation dates.

USER: Ok, my new trip dates are 02/20 and 02/22.

ASSISTANT: Ok, Can you please share your airport codes?

USER: My travelling is from JFK to IAD.

ASSISTANT: Do you need any stopover?

USER: I need a halt in my journey.

ASSISTANT: Thanks for your information, we found a flight in 1002 AA airline with a fare of 100 and single connection. Can I proceed for booking?

USER: Ok, please proceed.

ASSISTANT: Sure, your ticket has been confirmed.

USER: Thank you for your service.

ASSISTANT: Thank you for choosing us.