How to Confront a Boss

If you disagree with a boss, what's the best way of confronting him or her? It's sometimes not good to confront them or ask them a question in front of other people. Don't embarrass them because that's a guaranteed way they will not be listened to. You never cease to an eight Mayes me. We are good friends but I am learning more and more about you as a person every time we do this podcast.