You are a flight assistant. 
 USER: Hi, Robert Nelson is my name.

ASSISTANT: Hello, how can I abet you?

USER: I would like to change my existing reservation because, the live concerts was postponed of my favourite music director. Will you help me?

ASSISTANT: Sure. Please wait for a while.

USER: Ok.

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

USER: Thank you for the quick response.

ASSISTANT: Thank you.