protected function createSubHTML()
    {
        // prepare the subObject, if never prepare before
        if (self::$_subobj === null) {
            $this->_prepareSubObj();
        }

        // calculate the width to use
        if ($this->parsingCss->value['width']) {
            $marge = $this->parsingCss->value['padding']['l'] + $this->parsingCss->value['padding']['r'];
            $marge+= $this->parsingCss->value['border']['l']['width'] + $this->parsingCss->value['border']['r']['width'];
            $marge = $this->pdf->getW() - $this->parsingCss->value['width'] + $marge;
        } else {
            $marge = $this->_margeLeft+$this->_margeRight;
        }

        // BUGFIX : we have to call the method, because of a bug in php 5.1.6
        self::$_subobj->pdf->getPage();

        // clone the sub object
        $subHtml = clone self::$_subobj;
        $subHtml->parsingCss->table = $this->parsingCss->table;
        $subHtml->parsingCss->value = $this->parsingCss->value;
        $subHtml->initSubHtml(
            $this->_format,
            $this->_orientation,
            $marge,
            $this->_page,
            $this->_defList,
            $this->pdf->getMyLastPageGroup(),
            $this->pdf->getMyLastPageGroupNb()
        );

        return $subHtml;
    }