~~~ function loadJS (url, fn) { var ss = document.getElementsByName('script'), loaded = false; for (var i = 0, len = ss.length; i < len; i++) { if (ss[i].src && ss[i].getAttribute('src') == url) { loaded = true; break; } } if (loaded) { if (fn && typeof fn != 'undefined' && fn instanceof Function) fn(); return false; } var s = document.createElement('script'), b = false; s.setAttribute('type', 'text/javascript'); s.setAttribute('src', url); s.onload = s.onreadystatechange = function () { if (!b && (!this.readyState || this.readyState == 'loaded' || this.readyState == 'complete')) { b = true; if (fn && typeof fn != 'undefined' && fn instanceof Function) fn(); } }; document.getElementsByTagName('head')[0].appendChild(s); }, bind: function (objId, eventType, callBack) { //适用于任何浏览器的绑定 var obj = document.getElementById(objId); if (obj.addEventListener) { obj.addEventListener(eventType, callBack, false); }else if (window.attachEvent) { obj.attachEvent('on' + eventType, callBack); }else { obj['on' + eventType] = callBack; } } function JSLoad (args) { s = document.createElement("script"); s.setAttribute("type", "text/javascript"); s.setAttribute("src", args.url); s.onload = s.onreadystatechange = function () { if (!s.readyState || s.readyState == "loaded" || s.readyState == "complete") { if (typeof args.callback == "function") args.callback(this, args); s.onload = s.onreadystatechange = null; try { s.parentNode && s.parentNode.removeChild(s); } catch (e) { } } }; document.getElementsByTagName("head")[0].appendChild(s); } ~~~