title: javascript XMLHTTPRequest returning null in firefox
body: <p>I have a website I'm coding that is supposed to grab some XML from an external site and parse it, but it's giving me a typeError: xmlDoc is null. Not sure what's wrong and I was wondering if anyone could help.</p>
  
  <p>Here's teh code:</p>
  
  <p>EDIT: added changes</p>
  
  <pre><code>        function loadXML()
      {
  
          var XMLHttpRequestObject = false;
          if (window.XMLHttpRequest) {
              XMLHttpRequestObject = new XMLHttpRequest();
              XMLHttpRequestObject.overrideMimeType("text/xml");
              console.log("XML HTTP Request, xml override.");
  
          }
           else if (window.ActiveXObject) {
              XMLHttpRequestObject = new
              ActiveXObject("Microsoft.XMLHTTP");
              console.log("ActiveXObject xml request.");
          }
  
          if(XMLHttpRequestObject) {
              XMLHttpRequestObject.open("GET", xmlLink, true);
  
              XMLHttpRequestObject.onreadystatechange = function() {
                if (XMLHttpRequestObject.readyState == 4) {
                  // Load complete
                  var xmlDocument = XMLHttpRequestObject.responseXML;
                  parseXML(xmlDocument);
                }
              };
  
              XMLHttpRequestObject.send(null);
          }
      }
  
      function parseXML(xmlDoc){
          console.log(xmlDoc);
          var test1 = xmlDoc.getElementsByTagName('icon');
      }
  </code></pre>