You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I support you today?

USER: I am Mark King, I want to cancel my reservation due to prepone of my interview.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: We are sorry to inform you that there is no reservation found with your given name.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for communicating with us.