function createCookie(name,value,days) {
	if(days) {
		var date=new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

// Menu functionality

function menu_hide(node)
{
	//node.style.visibility="hidden";
	//node.style.display="none";
}


function menu_show(node)
{
	menu_collapse();

	node.style.visibility="visible";
	node.style.display="block";
}

function menu_collapse()
{
	var menu=document.getElementById('main_menu');

	for (child in menu.children)
	{
		node=menu.children[child];

		if (node.className=="sub_menu")
			menu_hide(node);
	}

}

var sub_menus=new Array();

function menu_toggle(num)
{
	if (num===false) return;

	if (sub_menus[num]) 
	{
       		if (sub_menus[num].style.visibility=="hidden") 
		{
			createCookie("menu_state",num,1);
			menu_show(sub_menus[num]);
		}
		else  menu_hide(sub_menus[num]);
	}
}

function menu_restore() {menu_toggle(readCookie("menu_state"));}

function menu_prepare()
{

	var menu=document.getElementById('main_menu');
	var item_button=document.getElementById('item_button');
	var last_node=false;

	var num=0;

	for (child in menu.children)
	{
		node=menu.children[child];

		if (node.className=="sub_menu")
		{
			if (last_node && last_node.className=="menu_item")
			{

			if (item_button.length)
			{
				item_button[num].node_num=num;
			} else 
			{
				item_button.node_num=num;
			}

				sub_menus[sub_menus.length]=node;
				num++;
			}
		}
		
		last_node=node;
	}

}