var lang = window.navigator.userLanguage;

if (lang == null)
    lang = window.navigator.language;
if (lang == null)
    lang = "en";
lang = lang.substr(0, 2);

var page = document.URL;
var idx = page.lastIndexOf("/");
var pre_page = page.substring(0, idx - 1);
var pre_idx = pre_page.lastIndexOf("/");
var page_lang;

if (pre_idx != -1)
    page_lang = page.substring(pre_idx + 1, idx);
//document.write("page_lang: " + page_lang + "; lang: " + lang);
if (page_lang != "rus" && page_lang != lang) {
    page = page.substr(idx);
    if (lang == "ru")
        window.location.assign("rus" + page);
}