var bgs = new Array ( "background-top-ingresso.jpg", "background-top-piscina.jpg", "background-top-piscina1.jpg", "background-top-tenda.jpg" );

var numBgs = bgs.length;
var c = 0; // Index of current image.
var rnum = Math.round(Math.random()*numBgs); // For the onLoad script

function randBg() {
   changeBg(rnum);
}

// Loads an image not quite random; based on the time, new every n minutes.
function loadBg(n) {
   Time = new Date();
   var Mins = Time.getMinutes();
   changeBg((Math.round(Mins/n)) % numBgs); // Next image every n minutes.
}

// Uncomment to preload images

var preload = new Array();
for (var i=0; i < numBgs; i++) {
	preload[i] = new Image;
	preload[i].src = bgs[i];
}

function changeBg(n) {
	document.getElementById("switcher").style.background = 'url(ui/s/normale/bgtop/' + bgs[n] + ') top no-repeat';
	c = n;
}

// Direction > 0 == forward, Direction < = 0 == back.
function goBg(direction) {
	var next;
	if (direction > 0) {
		if (c+1 == numBgs) next = 0;
		else next = c+1;
	} else if (direction <= 0) {
		if (c == 0) next = numBgs-1;
		else next = c-1;
	}
	changeBg(next);
}