function gEBID(id_elemento) {
	var elemento; // elemento da restituire
	
	if(document.getElementById) {
		elemento = document.getElementById(id_elemento); // IE > 5
	} else {
		elemento = document.all[id_elemento]; // IE < 5
	}
	
	return elemento;
}

function makeArray() { 
	this.length = makeArray.arguments.length 
	for (var i = 0; i < this.length; i++) {
		this[i+1] = makeArray.arguments[i];
	}
} 

function changeBg(htmlItem, url) {

	document.getElementById(htmlItem).style.background = url; // "url(images/agb_map.jpg)"
}

function swapHeadImages() {
	var images = new makeArray ("url(banner/banner1.jpg)", "url(banner/banner2.jpg)", "url(banner/banner3.jpg)", "url(banner/banner4.jpg)", "url(banner/banner5.jpg)", "url(banner/banner6.jpg)", "url(banner/banner7.jpg)", "url(banner/banner8.jpg)", "url(banner/banner9.jpg)", "url(banner/banner10.jpg)", "url(banner/banner11.jpg)", "url(banner/banner12.jpg)", "url(banner/banner13.jpg)", "url(banner/banner14.jpg)", "url(banner/banner15.jpg)", "url(banner/banner16.jpg)", "url(banner/banner17.jpg)", "url(banner/banner18.jpg)", "url(banner/banner19.jpg)", "url(banner/banner20.jpg)", "url(banner/banner21.jpg)");
	
	var index = Math.floor(Math.random() * (images.length + 0.5)); // valore casuale tra 1 e la lunghezza dell'array images

	changeBg("banner", images[index]);
	
//	document.getElementById("pippo").style.background = images[index]; // "url(images/agb_map.jpg)"

	setTimeout("swapHeadImages()", 30000); // Temporizzatore: 30 sec di attesa 
}

function zoom(theURL) {
  window.open(theURL,'zoom','width=200,height=200,scrollbars=no,resizable=yes');
}

function videoZoom(theURL) {
  window.open(theURL,'zoom','width=340,height=280,scrollbars=no,resizable=yes');
}

function approfondiZoom(theURL) {
  window.open(theURL,'Approfondimento','width=400,height=500,scrollbars=yes,resizable=yes');
}

function isOn(nr) {
	if (gEBID(nr).style.display == 'block') {
		return true;
	} else {
		return false;
	}
}

function displayOff(nr){
	if (isOn(nr)) { gEBID(nr).style.display = 'none'; }
}
function displayOn(nr){
	gEBID(nr).style.display = 'block';
}

function dlDisplayOn(nr) {
	dlSubDisplayOff();
	displayOn(nr);
}