gistfile1.js

__jsloader__ = function(scripts, callback, errorback) {
    var now = (new Date()) - 0;

    if (typeof errorback != 'function')
        errorback = function(url) { alert('jsloader load error: ' + url) };

    var load = function(url) {
        var script = document.createElement('script');
        script.type = 'text/javascript';
        script.charset = 'utf-8';
        var current_callback;
        if (scripts.length) {
            var u = scripts.shift();
            current_callback = function() { load(u) }
        } else {
            current_callback = callback;
        }
        if (window.ActiveXObject) { // IE
            script.onreadystatechange = function() {
                if (script.readyState == 'complete' || script.readyState == 'loaded')
                    current_callback();
            }
        } else {
            script.onload = current_callback;
            script.onerror = function() { errorback(url) };
        }
        script.src = url + '?' + now;
        document.body.appendChild(script);
    }

    load(scripts.shift());
}

//window.onload = function() {
//  __jsloader__(['a.js', 'b.js'], function() { alert('loaded') });
//}