var PLATFORM_LINUX=false;
var PLATFORM_MAC=false;
var PLATFORM_WINDOWS=false;
var BROWSER_NETSCAPE=false;
var BROWSER_MOZILLA=false;
var BROWSER_EXPLORER=false;
var BROWSER_OPERA=false;
var NOSCRIPT=false;
var BROWSER_SUBVERSION=0;
var BROWSER_DOM=false;
var BROWSER_VERSION=navigator.appVersion.substring(0,1);

if(navigator.appVersion.indexOf(".")>-1){
  BROWSER_SUBVERSION=navigator.appVersion.substr(navigator.appVersion.indexOf(".")+1,1);
}

if(window.opera) BROWSER_OPERA=true;
if(document.all) BROWSER_EXPLORER=true;
if(document.getElementById) BROWSER_DOM=true;
if(!BROWSER_EXPLORER && !BROWSER_OPERA && BROWSER_DOM) BROWSER_MOZILLA=true;
if(navigator.appName=="Netscape" && !BROWSER_MOZILLA){
  BROWSER_NETSCAPE=true;
}

if(navigator.platform.toUpperCase().indexOf("MAC")>-1) PLATFORM_MAC=true;
if(navigator.platform.toUpperCase().indexOf("WIN")>-1) PLATFORM_WINDOWS=true;
if(navigator.platform.toUpperCase().indexOf("LINUX")>-1) PLATFORM_LINUX=true;

if((BROWSER_NETSCAPE && parseInt(BROWSER_VERSION)<4) ||
   (BROWSER_NETSCAPE && parseInt(BROWSER_VERSION)==4 && parseInt(BROWSER_SUBVERSION)<7) ||
   (BROWSER_EXPLORER && parseInt(BROWSER_VERSION)<4) ||
   (!BROWSER_NETSCAPE && !BROWSER_EXPLORER && !BROWSER_MOZILLA && !BROWSER_OPERA) ||
   (PLATFORM_LINUX)){
   NOSCRIPT=true;
}

function alertBrowserValues()
{
  var text="Browser-Variablen:\n\n"+
           "BROWSER_OPERA=" + BROWSER_OPERA + "\n"+
           "BROWSER_EXPLORER=" + BROWSER_EXPLORER + "\n"+
           "BROWSER_NETSCAPE=" + BROWSER_NETSCAPE + "\n"+
           "BROWSER_MOZILLA=" + BROWSER_MOZILLA + "\n"+
           "BROWSER_DOM=" + BROWSER_DOM + "\n"+
           "BROWSER_VERSION=" + BROWSER_VERSION + "\n"+
           "BROWSER_SUBVERSION=" + BROWSER_SUBVERSION + "\n"+
           "PLATFORM_LINUX=" + PLATFORM_LINUX + "\n"+
           "PLATFORM_WINDOWS=" + PLATFORM_WINDOWS + "\n"+
           "PLATFORM_MAC=" + PLATFORM_MAC + "\n"+
           "NOSCRIPT=" + NOSCRIPT;
  alert(text);
}