function langUrl(url, lang)
{
    if (url.match(/http:\/\/[^\.]*\.[^\.]*\.[^\.]*\//)) {
        return url.replace(/http:\/\/[^\.]*\./, "http://" + lang + ".")
    }
    return url.replace(/http:\/\//, "http://" + lang + ".")
}
function _langUrl(url, lang)
{
    url_lang = lang
    if (lang == 'en') {
        url_lang = 'www'
    }
    var dest = "http://" + url_lang + "."
	var newUrl;
    if (new RegExp(/http:\/\/[^\.]*\.[^\.]*\.[^\.]*\//).test(url)) {
        newUrl = url.replace(/http:\/\/[^\.]*\./, dest)
    } else {
        newUrl = url.replace(/http:\/\//, dest)
	}

//	console.log("1: newUrl=" + newUrl)
    newUrl = newUrl.replace(/lang=[a-z]*\&?/gi, "")
//	console.log("2: newUrl=" + newUrl)
    var s = "?lang=" + lang
    //console.log(s)
	if (new RegExp(/\?/).test(newUrl)) {
		newUrl = newUrl.replace(/\?/, s)
//	    console.log("3: newUrl=" + newUrl)
	} else {
	    newUrl = newUrl + s
//	    console.log("4: newUrl=" + newUrl)
	}
	return newUrl;
}

function changeLang(lang)
{
    //console.log('changeLang: lang=' + lang)
    var s = _langUrl("" + window.location + "", lang)
	//how to debug javascralert(s);
    window.location.href = s
}