code: function submitForm(page, ph, callback) {
      var oldUrl;
      async.waterfall([
          function (callback) {
              page.get('url', function (url) {
                  oldUrl = url;
                  callback();
              });
          },
          function (callback) {
              page.evaluate(function () {
                  try {
                      document.forms[0].submit();
                      return null;
                  } catch (error) {
                      return error;
                  }
              }, function (error) {
                  // do this because if there is no error, the error is still something so we can't simply do callback(error, page, ph);
                  if (error) {
                      callback(error);
                      return;
                  }
                  callback()
              });
          }, function (callback) {
              checks.pageHasChanged(page, oldUrl, function (error) {
                  callback(error);
              });
          }
      ], function (error) {
          callback(error, page, ph);
      });
  }
docs: Submits a form on the page
  @param page
  @param ph
  @param {pageCallback} callback