<?php 
 if(isset($_COOKIE['uID']) && isset($_COOKIE['uHASH'])) 
 { 
     $user = mysqli_fetch_assoc(mysqli_query($mysqli, "SELECT * FROM `users` WHERE `uID` = '".intval($_COOKIE['uID'])."'")); 
  
     if(isset($user)) 
     { 
         if(($user['uHASH'] != $_COOKIE['uHASH'])) 
         { 
             unset($user); 
  
             setcookie('uID', '', time() - 60*60*24*365); 
             setcookie('uHASH', '', time() - 60*60*24*365); 
         } 
     } 
 }