Каптча (by Fuelen)

<?php
 
session_start();
 
$alp='QWERTYUIOPASDFGHJKLZXCVBNM123446789';
 
$len=strlen($alp);
 
$code=NULL;
 
$image = imagecreatetruecolor(72, 30);
 
$x = NULL;
 
$chars = mt_rand(4, 6);
 
for($i=0; $i<$chars; $i++)
 
{
 
$x+=rand(7, 11);
 
$code .= $symb = $alp{mt_rand(0,$len-1)};
 
imagechar($image, 5, $x, mt_rand(2, 14),$symb, 0x00FFFF);
 
}
 
 
 
$_SESSION['code'] = $code;
 
imagefilter($image, IMG_FILTER_EMBOSS);
 
header('Content-Type: image/png');
 
 
 
Imagepng($image);
 
ImageDestroy($image);
 
 
 
?>