You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, May I know your name?

USER: Sure, I am Stephen Lopez.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your name.

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

ASSISTANT: Thank you.