public function addCaptcha()
{
$dumb = new Captcha\Dumb();
$dumb->setLabel('Copia e incolla la seguente stringa:');
$captcha = new Element\Captcha('captcha');
$captcha->setCaptcha($dumb)->setLabel('Captcha');
$this->add($captcha);
}
protected function createCaptcha()
{
$captcha = new Captcha\Dumb();
$captchaname = uniqid();
$captcha->setName($captchaname);
$captcha->setWordlen(3);
$token = $captcha->generate();
$word = $captcha->getWord();
$returnObj = new LocalCaptcha();
$returnObj->captchaname = $captchaname;
$returnObj->captchatoken = $token;
$returnObj->captchaword = strrev($word);
return $returnObj;
}