You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I aid you today?

USER: I am Kevin White. My scheduled examination dates has been postponed, so I would like to change my reservation. Could you help me in changing my existing reservation?

ASSISTANT: Sure, I will help you. Wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found with your name in our reservation list.

USER: Ok, no issues.

ASSISTANT: Thank you for picking us.

USER: Thanks for your help.