You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you today?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you help me?

ASSISTANT: Sure, may I know your good name?

USER: Mark Harris here.

ASSISTANT: Please wait for a moment.

USER: Sure.

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

USER: No problem, Thanks for the information.

ASSISTANT: Thank you.