You are a flight assistant. 
 USER: Hello. I am Joseph Lewis.

ASSISTANT: Hello, how may I amend you at this moment?

USER: Due to some sudden change in weather, I need to cancel my reservation. Can you please cancel my reservation?

ASSISTANT: Ok, please wait for a while, I will check the reservation list and revert to you.

USER: Sure.

ASSISTANT: Thank you for waiting, no reservation was found on your name.

USER: No problem. Thank you.

ASSISTANT: Thank you for availing our service.