function daumenKino() {
		var $alt = $('#topnavi IMG.obersteebene');
		if($alt.next().length)
			var $neu = $alt.next();
		else
			var $neu = $('#topnavi IMG:first');

$alt.addClass('mittlereebene');
$alt.removeClass('obersteebene');
$neu.css({opacity: 0.0});
$neu.addClass('obersteebene');

$neu.animate({opacity: 1.0}, 3500, function() {
    $alt.removeClass('mittlereebene');
});
}