function fetch_object(idname)
{
	var my_obj = document.getElementById(idname);
	return my_obj;
}
function toggle_nav(obj)
{
	for (i = 0; i<= 8; i++ )
	{
		var sub_nav = fetch_object("sub_nav_" + i);
		if (obj == i)
		{
			sub_nav.style.display = "block";
		}
		else
		{
			sub_nav.style.display = "none";
		}
	}
}document.writeln('')