Quick and easy flood protection?

Question

I have a site where a user submits a message using AJAX to a file called like.php. In this file the users message is submitted to a database and it then sends a

Answer 1

If you want to stop flooding a search page you can try it like this way:

$flood_protection_interval = 2;
session_start();
if(
    isset($_SESSION['ip']) && 
    $_SESSION['counter'] > 10 &&
    $_SESSION['last_post'] + $flood_protection_interval > time()
    ){
        // $_SESSION['counter'] = 0; // Use this if you want to reset counter
        die("
\n\n\n\tFLOOD PROTECTION");
}
$_SESSION['counter']++;
$_SESSION['last_post'] = time();
$_SESSION['ip'] = $_SERVER['REMOTE_ADDR'];


So if your visitor search 10 times under e.g. 2 seconds he will be stopped!