You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: Due to some health issue, I want to change my existing reservation.

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

USER: Sure, please check the reservation on the name of Michelle Parker.

ASSISTANT: Sorry, we did not find any active reservation under your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for opting us.