var currentMenu = null;
var currentSubmenu = null;

function showMenu (menuId) {
	if (currentMenu != null) {
		if (currentSubmenu != null) {
			var element = getElement ("menu" + currentMenu + "sub" + currentSubmenu);
			if (element != null)
				element.style.display = "none";
			currentSubmenu = null;
		}

		var submenu = getElement ("menu" + currentMenu + "ext");
		var expander = getElement ("expander" + currentMenu);

		submenu.style.display = "none";
//		expander.src = "../Lnav_menu/images/expander"+menuId+".gif";
	}

	if (currentMenu != menuId) {
		var submenu = getElement ("menu" + menuId + "ext");
		var expander = getElement ("expander" + menuId);

		submenu.style.display = "inline";
//		expander.src = "kagyu/Lnav_menu/images/expander"+menuId+".gif";

		currentMenu = menuId;
	} else
		currentMenu = null;
}

function showSubmenu (menu, submenu) {
	if (currentSubmenu != null) {
		var element = getElement ("menu" + currentMenu + "sub" + currentSubmenu);
		if (element != null)
			element.style.display = "none";
	}
	
	var element = getElement ("menu" + currentMenu + "sub" + submenu);
	if (element != null)
		element.style.display = "inline";

	currentSubmenu = submenu;
}

function getElement (id) {

	return document.getElementById (id);
}