if (typeof window.XMLHttpRequest == "undefined") {
    if (typeof window.ActiveXObject == "function") {
        try {
            new ActiveXObject("Msxml2.XMLHTTP");
            window.XMLHttpRequest = function()
            {
                return new ActiveXObject("Msxml2.XMLHTTP");
            }
        }
        catch (e) {
            try {
                new ActiveXObject("Microsoft.XMLHTTP");
                window.XMLHttpRequest = function()
                {
                    return new ActiveXObject("Microsoft.XMLHTTP");
                }
            }
            catch (e) {
                // 試行を断念する
            }
        }
    }
    // else if (未知のブラウザ) { }
}
// else { /* Firefox, Opera, IE7 は何もしなくて良い */ }


load_url = function(url) {
    var req = new XMLHttpRequest();
    req.open('GET',url,false);
    req.send(null);
  if (req.status != 200) return '';
    return req.responseText;
}