Webdev:WAI-ARIA:Overview

Show Me the Money!

Before ARIA

 <div id="ads">
 ...
 </div>
 <div id="nav">
   <form id="searchform" ...>
     <input name="query" value="" />
   </form>
 ...
 </div>
 <div id="content">
   AJAX content inserted here...
 </div>

After ARIA

<div id="ads" role="banner">
...
</div>
<div id="nav" role="navigation">
    <form id="searchform" role="search" ...>
      <input name="query" value="" aria-required="true" />
    </form>
...
</div>
<div id="content" role="main" aria-live="assertive">
  AJAX content inserted here...
</div>