What part of no don't you understand? - Bumper stickerThe child that never hears no will have a hard time saying no. - Della Reese in "Touched by an Angel"Have you ever noticed how some of the most powerful things in life are also the most simple?So it is with the simply powerful word ``NO.''I've come to believe that one of the keys to success is the ability to say no when no is the best thing to say.Let's take a look at when to say no, and then more importantly, how to say NO effectively.When t.