public function getValue($sSelector)
    {
        $element = $this->getElementLazy($sSelector);
        $mValue = $this->_getValue($element->getXpath());

        try {
            $sType = $element->getAttribute('type');
        } catch (InvalidArgumentException $e) {
            sleep(1);
            $sType = $element->getAttribute('type');
        }
        if ($sType == 'checkbox') {
            $mValue = $mValue ? 'on' : 'off';
        }

        return trim($mValue);
    }