Levels take priority over depth assignments; therefore, when you’re swapping the depths of various objects, they must be on the same timeline in order for it to be effective. In most cases raising the depth of something on a lower level (such as changing the depths of symbols inside a movie clip) will not cause it to obscure something on a higher level.
For now, however, we’re not worried about levels; we’re just using layers and depths to create tabbed content navigation. Create three separate layers, each with not only the top tab, but also the full area of the page that will contain your content.
