function slideSwitch() {
  var $active = $('#imageaarray IMG.active');
  if ( $active.length == 0 ) $active = $('#imageaarray IMG:last');
  var $next =  $active.next().length ? $active.next()
      : $('#imageaarray IMG:first');

  // uncomment the 3 lines below to pull the images in random order
  //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()", 4000 );
});