echo "<img src='pic.php?'".session_id()." alt='kod'/><br/><br>
	Код с картинки:<br/>
	<input name='kod' type='text' size='5'/><br/>";

<?php
$font = 'includes/font.ttf';

session_id($_SERVER['QUERY_STRING']);
session_start();
$vercode = mt_rand(1000,10000);
$_SESSION['ref'] = $vercode;
header('Content-type: image/gif');

$img = imagecreatefromgif('images/codebg.gif');

imagecolorallocate($img, 255, 255, 255);
$imgcolor = imagecolorallocate($img, 0, 0, 0);

imagettftext($img, mt_rand(18, 19), mt_rand(-10, 10), mt_rand(0, 10), mt_rand(11, 32), $imgcolor, $font, substr($vercode, 0, 1));
imagettftext($img, mt_rand(18, 19), mt_rand(-10, 10), mt_rand(20, 25), mt_rand(11, 32), $imgcolor, $font, substr($vercode, 1, 1));
imagettftext($img, mt_rand(18, 19), mt_rand(-10, 10), mt_rand(35, 40), mt_rand(11, 32), $imgcolor, $font, substr($vercode, 2, 1));
imagettftext($img, mt_rand(18, 19), mt_rand(-10, 10), mt_rand(50, 55), mt_rand(11, 32), $imgcolor, $font, substr($vercode, 3, 1));

$imgpx = mt_rand(150,200);
while($imgpx > 0){
imagesetpixel($img, mt_rand(0, 75), mt_rand(0,35), $imgcolor);
$imgpx--;
}


imagegif($img);
?>

echo '<img src="pic.php'.session_id().'" alt="kod"/><br/><br>
	Код с картинки:<br/>
	<input name="kod" type="text" size="5"/><br/>';

session_start()