var count=0;
var name_list;
	
function imposta_sfondo(count){
	nascondi_sfondo();
	//---------------------------------------------------------------------
	document.getElementById("sfondo").src=name_list[count].url;
	document.getElementById("sfondo").style.width=name_list[count].width+"px";
	document.getElementById("sfondo").style.height=name_list[count].height+"px";
	var FullscreenrOptions = {bgID: '#sfondo' };
	jQuery.fn.fullscreenr(FullscreenrOptions);
	document.getElementById("n_sfondi").innerHTML= " "+(count+1)+"|"+name_list.length+" ";
	document.getElementById("autore_sfondo").innerHTML="© "+name_list[count].autore;
	};
	
function inizializza_sfondo(){
	oXHR=getXHR();
	oXHR.open("get","sfondi.php", true);
	oXHR.send(null);
	oXHR.onreadystatechange=function(){
		if(oXHR.readyState==4){
			if(oXHR.status==200){
				var json = oXHR.responseText;
				name_list= eval(json);
				imposta_sfondo(count);
				}
			}
		
		}
	}
	
function carica_sfondo_next(){
	count++;
	if (count==name_list.length){
	count=0;	
	}
	imposta_sfondo(count);
	}
	
function carica_sfondo_back(){
	count--;
	if (count==-1){
	count=name_list.length-1;
	}
	imposta_sfondo(count);
	}
	
function visualizza_sfondo(){
				document.getElementById("sfondo").style.visibility="visible";
				document.getElementById("corpo_pagina").style.visibility="visible";
				document.getElementById("loading").style.visibility="hidden";
		};
		
function nascondi_sfondo(){
				document.getElementById("loading").style.visibility="visible";
				document.getElementById("sfondo").style.visibility="hidden";
				document.getElementById("corpo_pagina").style.visibility="hidden";
		};