function show_layer(x)
{
	if(document.layers)
		document.layers[x].visibility="show";
	else
		document.all[x].style.visibility="visible";
}

function hide_layer(x)
{
	if(document.layers)
		document.layers[x].visibility="hide";
	else
		document.all[x].style.visibility="hidden";
}

var old;
var memold;
var subold;

if(document.layers)
{
        window.captureEvents(Event.MOUSEUP);
        window.onmouseup=do_out;
} else
{
        document.onmouseup=do_out;              // oder auch: document.onmouseclick=do_out
}


function do_menu(x)
{
	if(!old)
		old=memold;

	if(old!=x)
	{
		show_layer(x);
		old=x;
	} else
		old="";
}

function do_check(x)
{
	if(old && old!=x)
	{
		hide_layer(old);
		show_layer(x);
		old=x;
	}
	do_submenu();
}

function do_out()
{
	if(old)
		hide_layer(old);

	memold=old; old="";
	do_submenu();
}

function do_submenu(x)
{
	if(subold)
	{
		hide_layer(subold);
		subold="";
	}

	if(x)
	{
		show_layer(x);
		subold=x;
	}
}