You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you at this moment?

USER: I want to change my existing reservation due to some personal problems. Can you help me?

ASSISTANT: Sure, I am mirthful to help you with this.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Yes, I am Paul Taylor.

ASSISTANT: Please hold for a moment, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting, but I am sorry to tell you that, there is no active reservation found with your name in our database to change it.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you for approaching our agency, have a nice day.