function show_menu(which)
{
	var sub_menu = document.getElementById("sub_"+which);
	if(sub_menu)
	{
		sub_menu.style.display = "block";
	}
}

function hide_menu(which)
{
	var sub_menu = document.getElementById("sub_"+which);
	if(sub_menu)
	{
		sub_menu.style.display = "none";
	}
}