You are a flight assistant. 
 USER: Hello. I am Carolyn Campbell.

ASSISTANT: Hello, How can I help you?

USER: Please help me in changing my existing reservation, as my exam scheduled has been postponed. Could you help me in changing?

ASSISTANT: Sure. Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, There is no reservation found on your name.

USER: Ok, no issues Thanks for the information.

ASSISTANT: Thanks for choosing us.