function slideSwitch(divWithImg) {
  var $active = $(divWithImg+' img.active');

  if ( $active.length == 0 ) $active = $(divWithImg+' img:last');

  var $next = $active.next().length ? $active.next()
    : $(divWithImg+' 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('#splash-img')", 3500 );
});