Twitter status on title bar

// ==UserScript==
// @name           Twitter status on title bar
// @namespace      http://shinten.info/
// @author         watta
// @include        *
// ==/UserScript==

(function() {
    var title = document.title;
    GM_xmlhttpRequest({
        method: 'GET',
        url: 'http://twitter.com/statuses/friends_timeline.json',
        onload: function (req) {
            var responseText = req.responseText;
            var json;
            try {
                json = eval('(' + responseText + ')');
            } catch (e) {
                return;
            }
            var i = 0, m = json.length;
            var id = setInterval(function () {
                var u = json[i++];
                document.title = [
                    title, ' - ',
                    u.user.screen_name, ' : ', u.text
                ].join('');

//                 if (i == m) {
//                     clearInterval(id);
//                     document.title = title;
//                 }
                if (i == m) i = 0;
            }, 5000);
        },
        onerror: function (e) {
        }
    });
})();