code: public String buildCheckboxModifySiblings() {
  
          StringBuffer result = new StringBuffer(254);
          try {
              if (isMultiOperation() || (getCms().readSiblings(getParamResource(), CmsResourceFilter.ALL).size() > 1)) {
                  result.append("<tr>\n<td style=\"white-space:nowrap;\">");
                  result.append(key(Messages.GUI_AVAILABILITY_MODIFY_SIBLINGS_0));
                  result.append("</td>\n<td class=\"maxwidth\" style=\"padding-left: 5px;\">\n");
                  result.append("<input type=\"checkbox\" name=\"");
                  result.append(PARAM_MODIFY_SIBLINGS);
                  result.append("\" value=\"true\" style=\"text-align:left\">\n</td>\n<td>&nbsp</td></tr>");
              }
          } catch (CmsException e) {
              if (LOG.isInfoEnabled()) {
                  LOG.info(e);
              }
          }
          return result.toString();
      }
docs: Creates an the check box to modify all siblings.<p>
  
  If no siblings exist for this resource, an empty string will be returned.
  
  @return HTML code for the modify siblings check box.