code: function () {
          var http = false;
          // Use IE's ActiveX items to load the file.
          if (typeof ActiveXObject != 'undefined') {
              try {
                  http = new ActiveXObject("Msxml2.XMLHTTP");
              } catch (e) {
                  try {
                      http = new ActiveXObject("Microsoft.XMLHTTP");
                  } catch (E) {
                      http = false;
                  }
              }
              // If ActiveX is not available, use the XMLHttpRequest of Firefox/Mozilla etc. to load the document.
          } else if (window.XMLHttpRequest) {
              try {
                  http = new XMLHttpRequest();
              } catch (e) {
                  http = false;
              }
          }
          return http;
      }
docs: Create a xmlHttpRequest object - this is the constructor.