function slideShow() {
	
	//Inizializzo la variabile "active"
	var $active = $('#slideshow img.active');

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

	// 3 linee che servono per far comparire le immagini in ordine casuale
	var $sibs  = $active.siblings();
	var rndNum = Math.floor(Math.random() * $sibs.length );
	var $next  = $( $sibs[ rndNum ] );

	$active.addClass('last-active');
	
	//Determino l'opacità 
    $next.css({opacity: 0.0})
        .addClass('active')
        .animate({opacity: 1.0}, 1000, function() {
            $active.removeClass('active last-active');
        });
}

$(function() {
	//Eseguo la funzione
    setInterval( "slideShow()", 3000 );
});