function toHtml()
    {
        if ($this->_flagFrozen) {
            return parent::toHtml();
        } else {
            return '<input' . $this->_getAttrString(array(
                        'type'  => 'hidden',
                        'name'  => $this->getName(),
                        'value' => $this->_values[0]
                   )) . ' />' . parent::toHtml();

        }
    }