You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How could I support you?

USER: I am Christopher Hall. I want to cancel my reservation due to sudden change of my plan. Can you help me in cancelling my reservation?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: We did not find any reservation on your given name in our records.

USER: That's fine, thanks for your response.

ASSISTANT: Thank you for choosing us.