// JavaScript Document// JavaScript Document

// change photo #graphic
	var i=1;
	function backPhoto(){
		i--;
		if (i<1)
		{
		i=9;
		}
		document.getElementById('graphic').style.background="url(images/sfondo"+i+".jpg)"
		}
	function nextPhoto(){
		i++;
		if (i>9)
		{
		i=1;
		}		
		document.getElementById('graphic').style.background="url(images/sfondo"+i+".jpg)"
		}
// view or hide menu
function hideMenu()
{
	document.getElementById('menu').style.visibility="hidden";
	document.getElementById('precontent').style.visibility="hidden";
		document.getElementById('content').style.visibility="hidden";						
}
function showMenu()
{
	document.getElementById('menu').style.visibility="visible";
	document.getElementById('precontent').style.visibility="visible";
	document.getElementById('content').style.visibility="visible";
}

function toggleLayer(whichlayer)
{
	var stato = document.getElementById(whichlayer).style.display;										
	if( stato=='block' )
	{
	document.getElementById(whichlayer).style.display='none'; 					
	}else
	{
	document.getElementById(whichlayer).style.display='block'; 
	}
}