You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, we are glad to help you. Can I know your name please to proceed further?

USER: Sure, I am Andrew Lewis.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.