var menuitems = new Array("azienda", "servizi", "utilita");
	
	if(document.layers) // NS 4.x
		agent = "NS4";
	else if(document.all && !document.getElementById) // IE 4.x
		agent = "IE4";
	else if(document.getElementById) // W3C compliant: IE 5, IE 6, NS 6, Mozilla
		agent = "W3C";
	
	function show(idx)
	{
		if(idx <0 || idx >= menuitems.length)
			return;
	
		id = menuitems[idx];
		if(agent == "NS4")
			eval('document.' + id + '.visibility = "show"');
		else if(agent == "IE4")
			document.all[id].style.visibility = "visible";
		else if(agent == "W3C")
			document.getElementById(id).style.visibility = "visible";	
	}
	
	function hide(idx)
	{
		if(idx <0 || idx >= menuitems.length)
			return;
			
		id = menuitems[idx];
		if(agent == "NS4")
			eval('document.' + id + '.visibility = "hide"');
		else if(agent == "IE4")
			document.all[id].style.visibility = "hidden";
		else if(agent == "W3C")
			document.getElementById(id).style.visibility = "hidden";	
	}
	
	function visible(idx)
	{
		if(idx <0 || idx >= menuitems.length)
			return;
			
		id = menuitems[idx];
		if(agent == "NS4")
			return (eval('document.' + id + '.visibility') == 'show');
		else if(agent == "IE4")
			return(document.all[id].style.visibility == 'visible');
		else if(agent == "W3C")
			return(document.getElementById(id).style.visibility == 'visible');	
	}

	function toggle(idx) 
	{
		if(idx <=0 || idx > menuitems.length)
			return;
			
		for(i=0;i<menuitems.length;++i) {
			if(i==idx-1) {
				if(visible(i)) 
					hide(i);
				else
					show(i);
			}
			else {
				if(visible(i)) 
					hide(i);
			}
		}
	}

	function hideall() 
	{
		for(i=0;i<menuitems.length;++i) 
			hide(i);
	}