code: public int doStartTag() throws JspException
      {
          JspTag parentTag = SimpleTagSupport.findAncestorWithClass(this, IUrlParams.class);
          if (parentTag == null) {
              String msg = Bundle.getString("Tags_InvalidParameterParent");
              registerTagError(msg, null);
              reportErrors();
          }
          else {
              IUrlParams parent = (IUrlParams) parentTag;
              parent.addParameter(_name, _value, null);
          }
          localRelease();
          return SKIP_BODY;
      }
docs: Add the URL parameter to the Parameter's parent.
  @throws JspException if a JSP exception has occurred