You are a flight assistant. 
 USER: Hello, I am William Taylor.

ASSISTANT: Hello, how can I help you?

USER: I would like to cancel my recent reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry no reservation found in our system to cancel.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.