<?
srand((float) microtime() * 10000000);

  $image[1]['pic']='url/01.gif';
  $image[1]['link']='spondom.com/?ref=jamesbond';

  $image[2]['pic']='url/02.gif';
  $image[2]['link']='spondom2.com/?ref=jamesbond';

  $image[3]['pic']='url/03.gif';
  $image[3]['link']='spondom3.com/?ref=jamesbond';

  $rn = array_rand($image);
 
echo '<a href="'.$image[$rn]['link'].'" target="_blank">';
echo '<img src="'.$image[$rn]['pic'].'" width="468" height="60" /></a>';

?>