jsPerform.nonblock.dynamicScript.js - dynamically create and load js file to deliver better performance.

jsPerform.nonblock.dynamicScript.js

function loadScript(url, callback) {
    var script = document.createElement("script");
    script.type = "text/javascript";
    if (script.readyState) { //IE 
        script.onreadystatechange = function () {
            if (script.readyState == "loaded" || script.readyState == "complete") {
                script.onreadystatechange = null;
                callback();
            }
        };
    } else { //Others 
        script.onload = function () {
            callback();
        };
    }
    script.src = url;
    document.getElementsByTagName("head")[0].appendChild(script);
}