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function loadScript(url, callback) {
        var script = document.createElement("script");
        script.type = "text/javascript";
        script.id = "myscript";
        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);
    }