You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure. May I know your name please?

USER: Myself Christine Rodriguez.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.