public static function isIpIn($ipAddr, $net, $mask)
	{
		// doesn't check for the return value of ip2long
		$ipAddr	= ip2long($ipAddr);
		$rede	= ip2long($net);
		$mask	= ip2long($mask);
		$res	= $ipAddr & $mask;	// AND
		return ($res == $rede);
	}