var _url = document.URL;
var _http = (_url.substr(0,5) == "https") ? "https" : "http";
var _pos = _url.indexOf("://www.");

if(_pos < 0){
	//リダイレクト
	var u1 = _http + "://";
	var u2 = _url.substr(u1.length);
	location.href = u1 + "www." + u2;
}