var browserInfo      = navigator.userAgent.toLowerCase();
var theLanguage = "";

if (browserInfo.indexOf ('msie',0) != -1) {
   theLanguage = navigator.userLanguage.toLowerCase();
}else{
   theLanguage = navigator.language.toLowerCase();
}

if (theLanguage == "de") {
   self.location.href = "ger/index.htm";
}else{
   self.location.href = "en/index.htm";
}