function slideSwitch() {
    var visible = $('#testimonials li.visible');

    if ( visible.length == 0 ) visible = $('#testimonials li:last');

    var $next =  visible.next().length ? visible.next()
        : $('#testimonials li:first');
    
    var $sibs  = visible.siblings();
    var rndNum = Math.floor(Math.random() * $sibs.length );
	var $next  = $( $sibs[ rndNum ] );

    visible.addClass('last-visible')
		.animate({opacity : 0.0}, 1000);
	
    $next.css({opacity: '0.0'})
        .addClass('visible')
        .animate({opacity: '1.0'}, 2000, function() {
			visible.removeClass('visible last-visible');
        });
}

$(function() {
    setInterval( "slideSwitch()", 15000 );
});