function slideSwitch() {
   var $active = $('#slideshow DIV.active');

   if ( $active.length == 0 ) $active = $('#slideshow DIV:last');

   // use this to pull the divs in the order they appear in the markup
   var $next =  $active.next().length ? $active.next()
       : $('#slideshow DIV:first');

   // uncomment below to pull the divs randomly
   // var $sibs  = $active.siblings();
   // var rndNum = Math.floor(Math.random() * $sibs.length );
   // var $next  = $( $sibs[ rndNum ] );


   $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()", 4500 );
});