$validate = new Validate_Cpf();
var_dump($validate->isValid('Numero de CPF'));
		
$validate = new Validate_Cnpj();
var_dump($validate->isValid('Numero de CNPJ'));

// onde encontrar as classes de Validacao
$this->addElementPrefixPath(
	'Validate',
           APPLICATION_PATH .
		'/models/validate/',
		'validate'
);

$this->addElement('text', 'cpf', array (
	'filters' => array('StringTrim'),
	'validators' => array (
	     array('Cpf'),
	),
        'required' => true,
	'label' => 'CPF'
));


$this->addElement('text', 'cnpj', array (
	'filters' => array('StringTrim'),
	'validators' => array (
	     array('Cnpj'),
	),
        'required' => true,
	'label' => 'CNPJ'
));