title: differences between using wmode="transparent", "opaque", or "window" for an embedded object on a webpage
body: <p>when embedding a Flash object with the <code>&lt;object&gt;</code> and <code>&lt;embed&gt;</code> tag, there is an attribute called <code>wmode</code>. It seems that most of the time, <code>wmode="transparent"</code> is the same as <code>wmode="opaque"</code> as the Flash doesn't actually have any transparent color so that the bottom HTML element is to be shown.  As a result, <code>opaque</code> should be faster than <code>transparent</code> since it requires less processing for transparency, yet most of the time i see Flash object embedded with <code>transparent</code> instead of <code>opaque</code>.</p>
  
  <p><code>opaque</code> is needed so that other HTML element won't be covered up by the Flash object (such as a menu item that pops up an extra sub-menu won't be covered up by the Flash object).</p>
  
  <p>By the way, is there formal documentation for <code>wmode</code>'s <code>opaque</code>, <code>transparent</code>, and <code>window</code>?  I was only able to find blogs that describe it but not the formal documentation.  thanks.</p>