<?
$show = 2; //change 5 to number of buttons you want to show
$button[] = "|-img code here-|";
$button[] = "|-img code here-|";
//and so on

srand ((float) microtime() * 10000000);
$Keys = array_rand($button, 3); //change 5 to number of buttons you want to show

for($K = 0; $K < $show; $K++){
echo "".$button[$Keys[$K]]."";
}
?>

<?php

// Make this the relative path to the images, like "../img" or "random/images/".
// If the images are in the same directory, leave it blank.
$folder = 'fotos/banner/';

// Space seperated list of extensions, you probably won't have to change this.
$exts = 'jpg jpeg png gif';

$files = array(); $i = -1; // Initialize some variables
if ('' == $folder) $folder = './';
$handle = opendir($folder);
$exts = explode(' ', $exts);
while (false !== ($file = readdir($handle))) {
   foreach($exts as $ext) { // for each extension check the extension
       if (preg_match('/\.'.$ext.'$/i', $file, $test)) { // faster than ereg, case insensitive
           $files[] = $file; // it's good
           ++$i;
           }
       }
   }
closedir($handle); // We're not using it anymore
mt_srand((double)microtime()*1000000); // seed for PHP < 4.2
$rand = mt_rand(0, $i); // $i was incremented as we went along

header('Location: '.$folder.$files[$rand]); // Voila!
?>