docs: function doXDR(url, method, data, success, fail) {
          var req = support.getXDR();
          try {
              req.open(method, url);
              req.onload = function () { success(req); };
              // NOTE: IE (8/9) requires onerror, ontimeout, and onprogress
              // to be defined when making XDR to https servers
              req.onerror = function () { fail(req); };
              req.ontimeout = function () { fail(req); };
              req.onprogress = function () {};
              req.send(data);
          } catch (e) {
              return fail({
                  status: 0,
                  statusText: e.message
              });
          }
          return req;
      }