<? 
$antiflood_time = time() + 120;
$cookie = explode(",", $_COOKIE['antiflood']); 

if ($cookie[1] >= 5) 
{ 
    echo "<h1>Antiflood activated</h1>";
    
    echo "<p><b>Probeer het later opnieuw..</b></p>";
	exit(); 
} 
elseif ($cookie[0] == $_SERVER['PHP_SELF']) 
{ 
	$cookie[1]++;
	setcookie("antiflood", $_SERVER['PHP_SELF'] . "," . $cookie[1], $antiflood_time); 
} 
else 
{
	setcookie("antiflood", ""); 
	setcookie("antiflood", $_SERVER['PHP_SELF'] . ",1", $antiflood_time); 
} 
?> 

.. de rest van de php code of HTML ..