View file captcha.php

<?php
session_name("SID");
session_start();


$im = imageCreateFromGIF('img/captcha.gif');
$text = imageColorAllocate($im, 666, 666, 666);
$code = mt_rand(1000,9999);
$_SESSION['code']=$code;
imageString($im, 5, 8, 2, $code, $text);
ImageGIF($im);
ImageDestroy($im);
header("Content-Type: image/GIF");
?>