You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you for the day?

USER: Can you help me to amend my existing reservation?

ASSISTANT: Sure, I am here to help you with that changing reservation.

USER: Ok.

ASSISTANT: Can I know your name please to proceed for further?

USER: Myself Katherine Hall.

ASSISTANT: Please wait for a moment, let me check your previous reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting, but I am sorry to tell you that, there is no active reservation found with your name in our reservation list to change it.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.