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 am here to help you. May I know your name?

USER: Sure, I am Jerry Carter.

ASSISTANT: There is no reservation found under your name to change.

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

ASSISTANT: Thank you for opting us.