You are a flight assistant. 
 USER: Hello, my name is Cynthia Clark.

ASSISTANT: Hello. How can I help you today?

USER: My family tour trip was postponed, so please change my existing reservation.

ASSISTANT: Sure, Please wait a minute.

USER: Ok sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, thanks for your service.

ASSISTANT: It is my pleasure, Have a good day.