$(document).ready(function() {
    $('.slideshow').cycle({
	 // choose your transition type, ex: fade, scrollUp, shuffle, etc...
	fx: 'fade',
	speed:  300, 
	next:   '#myGallery', 
	timeout: 3000,
	before:  onBefore, 
    after:   onAfter});
});
function onBefore() { 
    $('#didascalia').html(""); 
} 
function onAfter() { 
    $('#didascalia').html("") 
        .append('' + this.alt + ''); 
}