#	#############################################################
#
#	Validação de CPF
# 
#	Faz validação de um número de CPF, retorna um BOOLEAN
#	Leonardo Giori (gambiarra.com.br)
#	http://creativecommons.org/licenses/by/2.5/
#
#	#############################################################

public function isCPF($number)
	{
		if(preg_match('/^\d{3}.\d{3}.\d{3}-\d{2}$/', $number))
			$number = preg_replace("/[^0-9]/","", $number);		
		$num = substr($number, 0, 9);
		for($n=10; $n>=2; $n--)
		{
			$o = (int) substr($num, (10 - $n), 1);
			$s1 = (int) $s1 + ($o * $n);
			$s2 = (int) $s2 + ($o * ($n + 1));
		}
		$d1 = (($s1 % 11)<2) ? 0 : (11 - ($s1 % 11));		
		$v 	= (($s2 + ($d1 * 2)) % 11);
		$d2 = ($v < 2) ? 0 : (11 - $v);
		return $number==$num.$d1.$d2;
	}

#	Exemplo #############################################################

if(isCPF("22233366638")){
	echo "CPF VÁLIDO!";
}else{
	echo "CPF INVÁLIDO!";
}