function rollImg() {
	// calculate random pic
	aImg = 1+Math.round(Math.random()*(photos.length-1));
	// set current img as bg
	node = YAHOO.util.Selector.query('img','pfoto',true);
	document.getElementById('pfoto').style.background = "url("+base+"data/promo/"+photos[aImg].filename+")";
	// wait and then do animation
	setTimeout("fadeoutImg();",1000);
}

function fadeoutImg() {
	// get node and fade it out
	var node = YAHOO.util.Selector.query('img', 'pfoto', true);
	aniObj = new YAHOO.util.Anim(node,{ opacity: {from: 1, to: 0 } },3,easing);
	aniObj.animate();
	setTimeout("showImg();",3000);
}

function showImg() {
	var node = YAHOO.util.Selector.query('img', 'pfoto', true);
	// set new src (already loaded by setting it as bg)
	node.src = base+"data/promo/"+photos[aImg].filename;
	if (photos[aImg].popis == 'null')
	{
		node.title = photos[aImg].popis;
	}
	else
	{
		node.title = "";
	}
	// make it visible
	aniObj = new YAHOO.util.Anim(node,{ opacity: {from: 0, to: 1 } },1,easing);
	aniObj.animate();
	setTimeout("rollImg();",1000);
}

var start = 1;
var base = document.getElementsByTagName('base')[0].href;
var easing = YAHOO.util.Easing.easeOut;

document.getElementById('pfoto').style.background = "url("+base+"data/promo/"+photos[aImg].filename+")";
setTimeout("rollImg();",1000);