load_script.js

function load_script(src) {
  var head = document.getElementsByTagName('head')[0],
      script = document.createElement('script');
  script.type = 'text/javascript';
  script.src = src;
  head.appendChild(script);
}

function load_jquery(version) {
  if(version == undefined) {
    version = '1.11.0'
  }
  load_script('http://ajax.googleapis.com/ajax/libs/jquery/' + version + '/jquery.min.js');
}