You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Due to some personal reason, I unable to catch my flight. Can you cancel my tickets?

ASSISTANT: Sure, can I know your name?

USER: Myself William Gonzalez.

ASSISTANT: Sorry William, there is no reservation found with your name to cancel.

USER: It's fine. Thank you for informing me.

ASSISTANT: It's my pleasure.