In Flash once we publish a file, we get a flattened .swf file. This file is usually embedded in an HTML page to put on a web site. But, we are not limited to just using this one .swf. In Flash, we can stack separate multiple .swf files one on top of another or set them inside Movie Clips in a main movie using the Load Movie action.

This is incredibly useful for loading in files that may be large and may not be even used in your movie, so you may want them only available if a user chooses them. It works great with making a jukebox. Setting audio files in seperate swf's to be loaded in when needed.

Loaded movies behave identically to movie Clips in relation to the main timeline. The only real difference is their target path. When we begin to stack .swfs one atop another their structure begins to resemble layers, like those on a timeline.

These movie layers are called Levels. The main timeline is always level 0 (referred to as "_level0"), and as additional movies are loaded on top, their corresponding level counts upward, _level1, _level2, and so on. This is important because in order to communicate with these movies to tell them to do things, like play and stop, you need to know where they are.

A loaded movie doesn't need to be loaded into the next empty level. We can load a movie to any level we like, even replacing our main movie at level 0.

If we load a movie to level that is already occupied by another file, then that file is replaced by the new file.

This is not the only way to use load movie. The easiest way to control and use load movie is to load movies into existing Movie Clips in your movie.

Like the main timeline, individual movie Clips have there own levels as well. So, within any movieclip we may load any number of files on any number of levels.

You can also unload your movies whenever you want if you are finished with them.

sample Load Movie Call loading a file into a Movie Clip symbol called "me":

loadMovie ("test.swf", "_root.me");

download some samples
one without a preloader for the loaded movie and one with a preloader.