ajax

gistfile1.js

<span id="ajaxButton" style="cursor: pointer; text-decoration: underline">
  Make a request
</span>
<script type="text/javascript">
(function() {
  var httpRequest;
  document.getElementById("ajaxButton").onclick = function() { makeRequest('test.html'); };

  function makeRequest(url) {
    if (window.XMLHttpRequest) { // Mozilla, Safari, ...
      httpRequest = new XMLHttpRequest();
    } else if (window.ActiveXObject) { // IE
      try {
        httpRequest = new ActiveXObject("Msxml2.XMLHTTP");
      } 
      catch (e) {
        try {
          httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
        } 
        catch (e) {}
      }
    }

    if (!httpRequest) {
      alert('Giving up :( Cannot create an XMLHTTP instance');
      return false;
    }
    httpRequest.onreadystatechange = alertContents;
    httpRequest.open('GET', url);
    httpRequest.send();
  }

  function alertContents() {
  	alert("trigger");
    if (httpRequest.readyState === 4) {
      if (httpRequest.status === 200) {
        alert(httpRequest.responseText);
      } else {
        alert('There was a problem with the request.');
      }
    }
  }
})();
</script>