You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Please change my existing reservation due to some health issues?

ASSISTANT: Sure, may I know your name for the changing process?

USER: Sure, I am Joshua Miller.

ASSISTANT: Wait a while, kindly.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our data base to change your previous booking.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.