var browser = navigator.appName
var ver = navigator.appVersion
var thestart = parseFloat(ver.indexOf("MSIE"))+1
var brow_ver = parseFloat(ver.substring(thestart+4,thestart+7))

/*
The variables do the following:
   1. browser: Gets the browser type (IE, Netscape, etc.).
   2. ver: Gets the version string. A long string of info with various bits of goo in it.
   3. the start: We need this number for the next part - trust me.
   4. brow_ver: This is the IE version number (generally 5.5, 6.0 or 7.0), converted from a string into an integer.
*/

if ((browser=="Microsoft Internet Explorer") && (brow_ver <= 6)) {
	window.location="browser_alert.php";
}