You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Please change my existing reservation due to some health issues?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: Sure, I am Charles Adams.

ASSISTANT: Please wait while I'll check your reservation status.

USER: Sure.

ASSISTANT: Charles Adams, there is no active reservation found under your name to do changes in that.

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

ASSISTANT: Thank you for choosing us.