You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: My name is Carol Harris. My business meeting was postponed, so please change my existing reservation.

ASSISTANT: Sure, I am happy to help you. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your given name. Thanks for choosing us.

USER: No problem, thank you for your service.