In this example, in which a short 9-second videoclip embedded in a swf (with stop actions in its first and last frames) is loaded and can be played with the play button, we've included keyframes in the play/pause control and the sound on/off control to display the visual state change. When the movie is playing, a pause button is displayed; when it is stopped, a play button shows. The sound button works in the opposite way, with the displayed state indicating the current state of the sound (off with a red line through it, on without). You should choose a display state which you think corresponds to one your user would expect.