You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: As I have a important meeting in my office, I want to cancel my reservation.

ASSISTANT: Sure, can I know your name please?

USER: William Anderson here.

ASSISTANT: Sorry Anderson, there is no reservation found in my database on your name.

USER: That's fine, thank you for checking.

ASSISTANT: Thank you for your positive response.

USER: Welcome.