You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER:  I would like to cancel my reservation due to sudden plan change in the trip, as our friends planned to go some other place this time, please help me by cancelling the ticket.

ASSISTANT: Sure, may I know your good name please.

USER: I am Mark Parker.

ASSISTANT: Ok, hold on for a moment please.

USER: Ok.

ASSISTANT: Sorry to say this Mark, there are no reservation found on your name.

USER: Ok, no problem. Thank you for your great service.

ASSISTANT: Welcome.