function getElement(elem) {
	if (typeof(elem) == 'string')
		return document.getElementById(elem);
	return elem;
}

function expand(mnu_id) {
	var menu = getElement(mnu_id);
	menu.style.display = 'block';
}

function collapse(mnu_id) {
	var menu = getElement(mnu_id);
	menu.style.display = 'none';
}

/*
var test_data = new Array(
	new Array('Link 0', 'index.php?id=0'),
	new Array('Link 1', 'index.php?id=1'),
	new Array('Link 2', 'index.php?id=2'),
	new Array('Link 3', 'index.php?id=3', new Array(
		new Array('Link 3:0', 'index.php?id=30'),
		new Array('Link 3:1', 'index.php?id=31'),
		new Array('Link 3:2', 'index.php?id=32'),
		new Array('Link 3:3', 'index.php?id=33', new Array(
			new Array('Link 3:3:0', 'index.php?id=330'),
			new Array('Link 3:3:1', 'index.php?id=331'),
			new Array('Link 3:3:2', 'index.php?id=332'),
			new Array('Link 3:3:3', 'index.php?id=333', new Array(
				new Array('Link 3:3:3:0', 'index.php?id=3330'),
				new Array('Link 3:3:3:1', 'index.php?id=3331')
			)),
			new Array('Link 3:3:4', 'index.php?id=334'),
			new Array('Link 3:3:5', 'index.php?id=335')
		))
	)),
	new Array('Link 4', 'index.php?id=4'),
	new Array('Link 5', 'index.php?id=5')
);
*/

function getMaxLeafLevel(a) {
	var c = 0;
	for (var i = 0; i < a.length; i++)
	{
		if (a[i].length == 3)
		{
			c++;
			c += getMaxLeafLevel(a[i][2]);
		}
	}
	return c;
}

var unique_id = 0;
function traverse(a, margin) {
	if (a != null && a.length > 0)
	{
		var html = '<ul>';
		for (var i = 0; i < a.length; i++)
		{
			if (a[i].length == 2)
			{
				// a[i][0] => tekst linka
				// a[i][1] => link
				
				if (margin == true)
					//html += '<li style="margin-left: 8px;"><a href="' + a[i][1] + '">' + a[i][0] + '</a></li>';
					html += '<li>&nbsp;&nbsp;&nbsp;<a href="' + a[i][1] + '">' + a[i][0] + '</a></li>';
				else
					html += '<li><a href="' + a[i][1] + '">' + a[i][0] + '</a></li>';
			}
			else
			{
				// zawiera submenu
				// a[i][0] => tekst linka
				// a[i][1] => link
				// a[i][2] => submenu
				var id = unique_id;
				unique_id++;
				html += '<div onmouseover="expand(\'mm' + id + '\');" onmouseout="collapse(\'mm' + id + '\');">';
				html += '<li><a href="' + a[i][1] + '">' + a[i][0] + '</a>';
				html += '&nbsp;&nbsp;<img src="img/arrow_dn.png" alt="" /></li>';
				html += '<div id="mm' + id + '" style="display: none">';
				html += traverse(a[i][2], true) + '</div></div>';
			}
		}
		html += '</ul>';
		return html;
	}
	return '';
}

function addMenuItems(menu_id, data) {
	var menu = getElement(menu_id);
	if (menu)
	{
		if (data != null && data.length > 0)
		{
			menu.innerHTML = traverse(data, false);
			return;
		}
		menu.className = '';
	}
}