anchor.diff:      }
   
       function disableActionButtonsIfNoFilesSelected() {
  -        $("#mergeButton, #removeButton").prop('disabled', !anyFileSelected());
  +        $("#removeButton").prop('disabled', !anyFileSelected());
  +    }
  +
  +    function disableMergeButtonIfNoFilesSelected() {
  +        $("#mergeButton").prop('disabled', !anyTwoFilesSelected());
       }
   
       var init = function() {
  
positive.code:     function anyFileSelected() {
          return $('input[name=selectedUserFile]:checked').length > 0;
      }
  
      function showStartWebformArea() {
          $("#startWebformArea").show();
  
negative.code:             actionForm.submit();
          });
          disableActionButtonsIfNoFilesSelected();
          disableMergeButtonIfNoFilesSelected();
          $('input[name=selectedUserFile]').change(disableActionButtonsIfNoFilesSelected);
          $('input[name=selectedUserFile]').change(disableMergeButtonIfNoFilesSelected);
      };
  
      $(init);
  