title: XmlHttpRequest Progress Eventhandler Compatibility in Internet Explorer
body: <p>My current AJAX application using jQuery looks as follows (simplified):</p>
  
  <pre><code>$.ajax({
      url: '/somefile',
      timeout : timeOutVar,
      success: function(data) {
          console.log('success');
      },
      error: function(data) {
          console.log('error');
      }
  });
  </code></pre>
  
  <p>I updated that code to use the <code>progress</code> eventhandler as follows.</p>
  
  <pre><code>$.ajax({
      url: '/somefile',
      timeout : timeOutVar,
      success: function(data) {
          console.log('success');
      },
      error: function(data) {
          console.log('error');
      },
      xhr: function() {
          var xhr = new window.XMLHttpRequest();
          xhr.addEventListener("progress", function(evt){
              console.log('progress');
          }, false);
          return xhr;
      }
  });
  </code></pre>
  
  <p>That works perfectly in Internet Explorer 10 and all other modern browsers. However, in older Internet Explorer version, I encountered a problem. IE9,8,7 do not call the <code>progress</code> eventhandler, but <code>success</code> when everything is loaded.</p>
  
  <p>So I wonder whether there are any compatibility issues in these older Internet Explorer versions. Unfortunately, I was not able to find any resource which exactly defines which parts of <code>XmlHttpRequest</code> work in which IE version. Does anybody know such a resource or what might be wrong in the code?</p>