Flash: Create a Preloader
http://www.flawebdeb.com/oct2002debtip.htm

Berg, Debbie
WebDeb
2002

Abstract:

Flash movies stream, so when the Flash movie contains several frames or scenes, the movie should be preloaded so that it will play back smoothly. Let's set up the animation that will play while the main movie (the presentation from a previous lesson) is loading behind the scenes. We'll create a movie clip for the preloader animation.