engine = null;
if (window.navigator.appName == "Microsoft Internet Explorer")
{
   // This is an IE browser. What mode is the engine in?
   if (document.documentMode) // IE8 or later
	  engine = document.documentMode;
   else // IE 5-7
   {
	  engine = 5; // Assume quirks mode unless proven otherwise
	  if (document.compatMode)
	  {
		 if (document.compatMode == "CSS1Compat")
			engine = 7; // standards mode
	  }
	  // There is no test for IE6 standards mode because that mode  
	  // was replaced by IE7 standards mode; there is no emulation.
   }
   // the engine variable now contains the document compatibility mode.
}