code: private String buildInternalForm() {
  
          StringBuffer result = new StringBuffer(128);
  
          CmsResource resource = null;
          boolean internal = false;
  
          // try to read the internal flag from the resource
          try {
              resource = getCms().readResource(getParamResource(), CmsResourceFilter.ALL);
              internal = resource.isInternal();
          } catch (CmsException e) {
              // an error occurred reading the resource
              LOG.error(e.getLocalizedMessage());
          }
  
          if ((resource != null) && (resource.isFile())) {
              // only show internal check box on files
              result.append("<form action=\"").append(getDialogUri()).append(
                  "\" method=\"post\" name=\"internal\" class=\"nomargin\">\n");
              result.append("<table border=\"0\" width=\"100%\">\n");
              result.append("<tr>\n");
              result.append("\t<td class=\"dialogpermissioncell\">").append(key(Messages.GUI_PERMISSION_INTERNAL_0));
              result.append(" <input type=\"checkbox\" name=\"");
              result.append(PARAM_INTERNAL);
              result.append("\" value=\"true\"");
              if (internal) {
                  result.append(" checked=\"checked\"");
              }
              if (!getEditable()) {
                  result.append(" disabled=\"disabled\"");
              }
              result.append(" ></td>\n");
              if (getEditable()) {
                  result.append("<td><input  type=\"submit\" class=\"dialogbutton\" value=\"").append(
                      key(Messages.GUI_LABEL_SET_0)).append("\">");
              }
              result.append("</td>\n");
              result.append("</tr>\n");
              result.append("</table>\n");
              setParamAction(DIALOG_INTERNALUSE);
              setParamType(null);
              setParamName(null);
              result.append(paramsAsHidden());
              result.append("</form>\n");
          }
          return result.toString();
  
      }
docs: Builds a String with HTML code to display the form to add a new access control entry for the current resource.<p>
  
  @return HTML String with the form