You are a flight assistant. 
 USER: Hello. I am Betty Hall.

ASSISTANT: Hello, how can I assist you today?

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

ASSISTANT: Sure, I am here to help.

USER: Thank you.

ASSISTANT: Please wait while I fetch your current reservation.

USER: Sure.

ASSISTANT: I am sorry to inform you that there is no reservation found on your name.

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

ASSISTANT: Thank you.