code: @Override
      protected String defaultActionHtmlContent() {
  
          StringBuffer result = new StringBuffer(2048);
          result.append("<form name=\"EDITOR\" id=\"EDITOR\" method=\"post\" action=\"").append(getDialogUri());
          result.append("\" class=\"nomargin\" onsubmit=\"return submitAction('").append(DIALOG_OK).append(
              "', null, 'EDITOR');\">\n");
          result.append(dialogContentStart(null));
          result.append(buildDialogForm());
          result.append(dialogContentEnd());
          result.append(dialogButtonsCustom());
          result.append(paramsAsHidden());
          if (getParamFramename() == null) {
              result.append("\n<input type=\"hidden\" name=\"").append(PARAM_FRAMENAME).append("\" value=\"\">\n");
          }
  
          // add script for filtering categories
          result.append(filterCategoryJS());
          result.append("</form>\n");
  
          // get search results if query was more than nothing
          // we have to retrieve them before category search results are available because
          // those are collected as a side effect of search iteration.
          String searchResults = createSearchResults();
  
          // append category search results if there...
          result.append(createCategorySearchResultHtml());
          result.append(searchResults);
  
          result.append(getWidgetHtmlEnd());
          // Normalize the previous encoded query value on client side
          result.append(normalizePreviousQueryJS());
  
          return result.toString();
      }
docs: Returns the html code for the default action content.<p>
  
  Overrides <code> {@link org.opencms.workplace.CmsWidgetDialog#defaultActionHtml()}</code>
  in order to put additional forms for page links and search results after OK - CANCEL buttons
  and outside the main form.<p>
  
  @return html code