You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Margaret Clark.

ASSISTANT: How can I help you Mr. Clark?

USER: I have already reserved my ticket, but right now I want to cancel that reservation.

ASSISTANT: OK. Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry Mr. Clark, I don't found any reservation with your name.

USER: OK fine,. Thank you for your wonderful service.

ASSISTANT: It's my pleasure.