Simple PHP proxy detector

$fp = fsockopen($_SERVER[REMOTE_ADDR], 9050, $errno, $errstr, 5);
if (!$fp) {
	// port is closed or blocked
} else {
	// port is open and available
	echo "Proxie detected.";
	fclose($fp);
	die();
}
$fp = fsockopen($_SERVER[REMOTE_ADDR], 3128, $errno, $errstr, 5);
if (!$fp) {
	// port is closed or blocked
} else {
	// port is open and available
	echo "Proxie detected.";
	fclose($fp);
	die();
}
$fp = fsockopen($_SERVER[REMOTE_ADDR], 80, $errno, $errstr, 5);
if (!$fp) {
	// port is closed or blocked
} else {
	// port is open and available
	echo "Proxie detected.";
	fclose($fp);
	die();
}

$fp = fsockopen($_SERVER[REMOTE_ADDR], 8080, $errno, $errstr, 5);
if (!$fp) {
	// port is closed or blocked
} else {
	// port is open and available
	echo "Proxie detected.";
	fclose($fp);
	die();
}