"Layers" is a feature of HTML and CSS that allows content that is
arranged logically in a document to be displayed visually in another
layout.  There are layer codes (z-index) that determine which layer is
on top, and which is under.  By setting the z-index, presentation order
can be changed.

In the background, layers are created using the <div></div> markup,
which will be ignored by many types of assistive technologies.  This is
what allows accessible pages to be created with layers - they can be
invisible to those who need access.

However, because the visual presentation is not necessarily the same as
the logical presentation, it is critical that a page designed with
layers be constructed so that, with the layers turned off, the page
makes sense.  This is where many designers can mess things up.  The
page should be designed first so that the content is in logical order,
then the layers used to provide the desired visual presentation, with
the awareness that not everyone will see the "visual" order.

Denis Anson


Karen Guo wrote:


>Our College is developing a new website as well. And the they plan to
use
>a lot of layers to present the content. It seems to very convenient to
put
>content on different layers and all of the layers are on only one html
>page. They use one layer for main navigation bar, one layer for
secondary
>navigation bar, and one layer for content. I can tab to some links, but
I
>don't feel the links are in order, from main menu to sub menu and the
>content.
>
>Could layers be accessible? Is there a way to order the layers?
>Will "tabindex" work with layers?
>
>karen Guo
>Technology Assistant
>Teachers College
>

--------------------
Denis Anson, MS, OTR
Assistant Professor
College Misericordia
301 Lake St.
Dallas, PA 18612
Phone: 570-674-6413