Program PHP Captcha Background Berubah-Ubah

BERIKUT PROGRAM PHP CAPTCHA BACKGROUND BERUBAH-UBAH DAN INI CARA-CARANYA

<?php

session_start();

$alphaNumeric = "abcdefghijklmnopqrstuvwxyz0123456789";

$random = substr(str_shuffle($alphaNumeric), 0, 6);

$bg = rand(1, 5);

$image = imagecreatefromjpeg("bg$bg.jpg");

$textcolor = imagecolorallocate ($image, 235, 270, 300);

imagestring ($image, 3, 9, 8, $random, $textcolor);

$_SESSIONS['image_random_value'] = md5($random);

header('Content-type: image/jpeg');

imagejpeg($image);

imagedestroy($image);

?>

JIKA ADA KESULITAN ATAU KESALAHAN, JANGAN SEGAN-SEGAN UNTUK BERTANYA