You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I would like to cancel my existing reservation as I have to attend a meeting on my journey date. Can you help me?

ASSISTANT: Sure, I am delighted to help you. May I know your good name please?

USER: My name is Stephen Young.

ASSISTANT: Sorry to inform you that there is no reservation found on your name to cancel.

USER: I guess I have cancelled it before. Anyways, thank you for the information.

ASSISTANT: Thank you for contacting us.