if(window.document.all)
  var browserLanguage = navigator.userLanguage;
else
  var browserLanguage = navigator.language;

switch(browserLanguage)
  {
   case "de":
     top.location.href = "german/home/index.html";
   break;
   case "fr":
     top.location.href = "german/home/index.html";
   break;
   case "en":
   default:
     top.location.href = "german/home/index.html";
   break;
  }