Image randomizer

reddit-tribes-header-image.php

<?php                                                                               

$image_urls = array(
  'http://b.thumbs.redditmedia.com/crFh5ZpigMuuO68U.png',
  'http://i.imgur.com/Boqat.png',
  'http://i.imgur.com/gwfE3.png',
  'http://i.imgur.com/WRBMg.png',
  'http://i.imgur.com/C1fqv.png',
  'http://i.imgur.com/Ycc5g.png',
  'http://i.imgur.com/wsow1.png'
);

if (isset($_GET['random'])) {
  // random each time
  $index = array_rand($image_urls);
} else {
  // changes each day
  $index = date('j') % count($image_urls);
} 

header('Location: '.$image_urls[$index]);