code: public int getIdByTag(String tag)
      {
          Integer value = (Integer) table.getValueByKey(tag);
          if (value == null)
              LoggerFactory.getDefaultLogger().error(
                  "** " + this.getClass().getName() + ": Tag '" + tag + "' is not defined. **");
          return value.intValue();
      }
docs: returns the repository element id associated with the xml-tag
  literal <code>tag</code>.
  @return the resulting repository element id.
  @throws NullPointerException if no value was found for <b>tag</b>