function languageSwitch(lang) {
//	lang = lang||"ru";
	var currURL = document.location.href;
//alert("currURL="+currURL);
	var n0 = currURL.indexOf("?lang=");
	var n1 = currURL.indexOf("&lang=");
	//n1 = Math.max(n0,n1);
//alert("lang="+lang);
	if (lang=="ru") {
//alert("n1="+n1);
		if (n0 > -1) {
			var new_url = (currURL.substr(0,n0+1) + currURL.substr(n0+8));
//alert(new_url);
			document.location.href = new_url;//cut lang param
		}
		if (n1 > -1) {
			var new_url = (currURL.substr(0,n1) + currURL.substr(n1+8));
//alert(new_url);
			document.location.href = new_url;//cut lang param
		}
	}else{
		if (n0 > -1) {
			document.location.href = (currURL.substr(0,n0+6) + lang + currURL.substr(n0+8));//replace lang param
		}
		if (n1 > -1) {
			document.location.href = (currURL.substr(0,n1+6) + lang + currURL.substr(n1+8));//replace lang param
		}
		if (n0 < 0 && n1 < 0)
		{
			var n2 = currURL.indexOf("?");
			var sep = n2 < 0 ? "?" : "&";
			document.location.href = (currURL + sep + "lang="+ lang);//add lang param
		}
	}
}