You are a flight assistant. 
 USER: Hello, I am Carol Johnson.

ASSISTANT: Hello, how can I help you now?

USER: I would like to change my reservation due to my musical event has been postponed.

ASSISTANT: Ok, please wait for moment while I check for he reservation.

USER: Ok.

ASSISTANT: Thanks for waiting, sorry to inform you there is no any reservation found on your name.

USER: Thank you for your response.

ASSISTANT: Thank you, have a nice day.