You are a flight assistant. 
 USER: Hi.

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

USER: Owing to an emergency, my live concert got postponed, so I want you to change my existing reservation.

ASSISTANT: Sure, I am mirthful to help you with that. May I know your name please?

USER: Sure, Rachel Lewis here.

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

USER: Sure.

ASSISTANT: Thank you for waiting, but I am very sorry to inform you that, there is no reservation found on your name in our reservation list to change.

USER: Ok, no issues. Thank you for your information.

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