You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name please?

USER: I'm Matthew Carter.My business meeting has been postponed, so I would like to change my existing reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: You are welcome.