var menu_ids = [];
var menu_transitioning = false;

function toggle_menu(menu_id) {
	var id = "submenu" + menu_id;
	var opts = {afterFinish: function() { menu_transitioning = false }};
	if(!menu_transitioning) {
		menu_transitioning = true;
		
		if($(id).style.display == 'none') {
			// turn off any menus that are on (should only be one submenu)
			
			for(var i = 0; i < menu_ids.length; ++i) {
				if(menu_ids[i] != menu_id && $("submenu" + menu_ids[i]).style.display != 'none') {
					Effect.Phase("submenu" + menu_ids[i]);
				}
			}
			
			Effect.Phase(id, opts);
		} else {
			Effect.Phase(id, opts);
		}
	}
}

function setup_menu() {
	var nav = document.getElementById("nav");
	var anchors = nav.getElementsByTagName("A");
	var idprefix = "parent_link";
	for(var i = 0; i < anchors.length; ++i) {
		var anchor = anchors[i];
		if(anchor.className == "parent-link") {
			var parent_id = anchor.id.substr(idprefix.length);
			menu_ids[menu_ids.length] = parent_id;
			anchor.href = "javascript:void(0)";
			anchor.onclick = function(id) { return function() { toggle_menu(id) } } (parent_id);

		}
	}
}