current_active="none";

function hideLayer(name)
{
	if (document.all) // Internet Explorer
		document.all[name].style.visibility="hidden";
	else if (document.layers) // Netscape 4
		document.layers[name].visibility="hide";
	else if (document.getElementById) // IE 5 / 6 or NN 6
		document.getElementById(name).style.visibility="hidden";
}

function showLayer(name)
{
	if (document.all) // Internet Explorer
		document.all[name].style.visibility="visible";
	else if (document.layers) // Netscape 4
		document.layers[name].visibility="show";
	else if (document.getElementById) // IE 5 / 6 or NN 6
		document.getElementById(name).style.visibility="visible";
}

function switchLayer(name) // hides visible layers and shows hidden ones
{
	if (document.all) // Internet Explorer
		document.all[name].style.visibility = (document.all[name].style.visibility == "hidden") ? "visible" : "hidden";
	else if (document.layers) // Netscape 4
		document.layers[name].visibility = (document.layers[name].visibility == "hide") ? "show" : "hide";
	else if (document.getElementById) // IE 5 / 6 or NN 6
		document.getElementById(name).style.visibility = (document.getElementById(name).style.visibility == "hidden") ? "visible" : "hidden";
}

function hideLayers(layer_array)
{
	for (i = 0; i < layer_array.length; i++)
	  hideLayer (layer_array[i]);
}

function showLayers(layer_array)
{
	for (i = 0; i < layer_array.length; i++)
	  showLayer (layer_array[i]);
}

function nascondi(n)
{
	if (isNaN(current_active)) return;
	if (document.all) // Internet Explorer
		document.all["menubar_"+n].style.visibility="hidden";
	else if (document.layers) // Netscape 4
		document.layers["menubar_"+n].visibility="hide";
	else if (document.getElementById) // IE 5 / 6 or NN 6
		document.getElementById("menubar_"+n).style.visibility="hidden";
}

function mostra(n)
{
	if (n==current_active)
	{
		nascondi(n);
		current_active="none";
		return;
	}
	if (n==1)
	{
		current_active="none";
		return;
	}
	if (document.all) // Internet Explorer
		document.all["menubar_"+n].style.visibility="visible";
	else if (document.layers) // Netscape 4
		document.layers["menubar_"+n].visibility="show";
	else if (document.getElementById) // IE 5 / 6 or NN 6
		document.getElementById("menubar_"+n).style.visibility="visible";
	current_active=n;
}