You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Richard Scott. Suddenly my trip plan is changed.So I want to cancel my reservation.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation has been found on your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for choosing us.