AJAX

<pre id="target"></pre>
<script type="text/javascript">
  function get(url, k) {
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
      if (this.readyState === 4 && this.status === 200) {
        k(xhr.responseText);
      }
    }
    xhr.open('GET', url, true);
    xhr.send();
  }

  get('/james.json', function (x) {
    document.getElementById('target').innerHTML = x;
  });
</script>

Demo