You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I have to change my existing reservation because of my health issues. Can you please help me out?

ASSISTANT: Sure, I will help you with the change of flight reservation.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, my name is Eric Taylor.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, Eric I could not find any flight reservation on your name.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your information.