function slideSwitch(switchSpeed) {
	var $active = $('#slideshow IMG.active');
    
    if ( $active.length == 0 ) $active = $('#slideshow IMG:last');

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

$(function() {
    setInterval ( "slideSwitch(2000)", 4000 );    
});