You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Rachel Turner.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no active reservations on your name to change.

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

ASSISTANT: Thank you for reaching our service.