You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Gary Evans. I want to change an existing reservation, due to my client meeting was postponed.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, no reservation found with your name.

USER: Not an issue. Thanks for your service.

ASSISTANT: Thank you.