You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Anthony Phillips.

ASSISTANT: Ok.

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

ASSISTANT: Sure, please hold on for a moment. I am sorry, there are no reservations with your name.

USER: That's fine.

ASSISTANT: Thank you, have a good day.

USER: Thank you for your service.