Working with Movie Clips and Buttons > About multiple Timelines |  |

About multiple Timelines

The Flash Player has a stacking order of levels. Every Flash movie has a main Timeline located at level 0 in the Flash Player. You can use the `loadMovie` action to load other Flash movies (SWF files) into the Flash Player at different levels. If you load movies into levels above level 0, the movies lie on top of each other like drawings on transparent paper; where there is no content on the Stage, you can see through to the content on lower levels. If you load a movie into level 0, it replaces the main Timeline. Each movie loaded into a level of the Flash Player has its own Timeline.

Flash movies at any level can have movie clip instances on their Timelines. Each movie clip instance also has a Timeline and can contain other movie clips that also have Timelines. In the Flash Player, levels and Timelines are arranged hierarchically so that you can organize and easily control the objects in your movie.

The hierarchy of levels and movie clips in the Flash Player

In Flash, this hierarchy of levels and movie clips is called the display list. When you author in Flash, you can view the display list in the Movie Explorer; when you play the movie in test mode, the stand-alone Flash Player, or a Web browser, you can view the display list in the Debugger.

The Movie Explorer shows the display list.

Depending on their locations in the display list, Timelines have specific relationships with each other. A child Timeline nested inside another Timeline is affected by changes made to the parent Timeline. For example, if `portland` is a child of `oregon` and you change the `_xscale` property of `oregon`, `portland` will also scale.

Timelines can also send messages to each other. For example, an action on the last frame of one movie clip can tell another movie clip to play.