Hello,.
Hello, firstly may I know your name please?
I am Brian Davis.
Davis, how can I assist you now?
I want to change my existing reservation as my plan to visit Museum of  fine arts got rescheduled.
Ok, please wait for a while.
Ok.
Sorry Davis, there is no reservation found on your name.
That's fine, thank you for the information.
Thank you for approaching us, have a nice day.