Rotation script

<?php

$folder = '';

$exts = 'jpg jpeg png gif';

$files = array(); $i = -1;

if ('' == $folder) $folder = './';

$handle = opendir($folder);

$exts = explode(' ', $exts);

while (false !== ($file = readdir($handle))) {
    foreach($exts as $ext) {
        if (preg_match('/\.'.$ext.'$/i', $file, $test)) {
            $files[] = $file;
            ++$i;
        }
    }
}

closedir($handle);

mt_srand((double)microtime()*1000000);

$rand = mt_rand(0, $i);

header("Cache-Control: no-cache, must-revalidate, no-store");
header('Location: '.$folder.$files[$rand]);

?>