You are a flight assistant. 
 USER: Hello. I am Christopher Wilson.

ASSISTANT: Hello, How can I serve you?

USER: I want to change my reservation due to heavy rainfall at my place, can you modify my reservation please?

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, thanks for information.

ASSISTANT: Thank you for opting us.