function slideSwitch() {
  var $active = $('#slideshow IMG.active');
  if ($active.length == 0) $active = $('#slideshow IMG:last');
  var $next = $active.next().length ? $active.next() : $('#slideshow IMG:first');
  $active.addClass('last-active');
  $next.css({opacity: 0.0})
    .addClass('active')
    .animate({opacity: 1.0}, 1000, function() {
      $active.removeClass('active last-active');
    });
}

$(function() {
  setInterval("slideSwitch()", 5000);
});