Anti Flood php.

<?php


 if (!isset($_SESSION)) {
         session_start();
 }

 if($_SESSION['last_session_request'] > (time() - 5)){
    if(empty($_SESSION['last_request_count'])){
        $_SESSION['last_request_count'] = 1;
    }elseif($_SESSION['last_request_count'] < 5){
        $_SESSION['last_request_count'] = $_SESSION['last_request_count'] + 1;
    }elseif($_SESSION['last_request_count'] >= 5){
            header("location: http://www.google.com/");
            exit;
         }
 }else{
    $_SESSION['last_request_count'] = 1;
 }

 $_SESSION['last_session_request'] = time();

 ?>