You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Owing an emergency, I want to cancel my reservation. Can you help me for that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Sure, my name is Donald Green.

ASSISTANT: Sorry Donald, no reservation found on your name to cancel your reservation.

USER: That's ok, my booking may not be reserved.

ASSISTANT: Welcome, have a nice day.