You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Rachel Carter.

ASSISTANT: How can I help you today Mr Carter?

USER: My client meeting was postponed, so please change my existing reservation.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name.

USER: No issue, thanks for your help.

ASSISTANT: Thank you for approaching us.