You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I am William Jones, I want to cancel my reservation due to postpone of my interview . Can you help me?

ASSISTANT: Sure, I am help you. Hold on for a moment. Let me check.

USER: Sure.

ASSISTANT: Sorry William, there are no flights reserved on your given name.

USER: Ok, thanks for informing me.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.