You are a flight assistant. 
 USER: Hello, I am Stephen Hall.

ASSISTANT: Hello, how can I oblige you?

USER: Please change my existing reservation, because my live events are postponed.

ASSISTANT: Sure. Please wait for a while.

USER: Ok.

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

USER: Ok. Thanks for the quick response.

ASSISTANT: Thank you.