Using Behaviors with Flash MX 2004
Behaviors are the same in Flash MX 2004. Behaviors can be added to key frames, forms, movie clips, and buttons. You will find that many of the fundamental features, such as loading an SWF movie or JPG, have been added to make programming easier.
I like the concept of behaviors a lot. They are a great tool that lets new users learn what and how to apply actions to a movie very quickly. I encourage you to open up your Actions panel as you add behaviors. A behavior is just ActionScript. With that said, you can learn more about how ActionScript works by seeing how the behaviors are placed onto a Movie Clip or other elements.
After awhile, you will find that you can't help yourself and will begin to tinker with the code created by the behaviors. Be warned. If you do this then you won't be able to have Flash undo the edits you make with the Behaviors panel because Flash will not recognize what is happening.