Get Script

getscript.js

function getScript(src, callback) {
    var script = document.createElement('script');
    script.src = src + '?nc=' + new Date().getTime();

    var done = false;

    script.onload = script.onreadystatechange = function () {
      if (!done && (!this.readyState
          || this.readyState === 'loaded'
          || this.readyState === 'complete')
          ) {
        done = true;
        callback();

        /* Handle memory leak in IE */
        script.onload = script.onreadystatechange = null;
        document.head.removeChild(script);
      }
    };

    document.head.appendChild(script);
  }