var pijl18x13	= new Image();
pijl18x13.src	= 'images/pijl18x13.gif';
var niks18x13	= new Image();
niks18x13.src	= 'images/niks18x13.gif';

var menuOn = '';
var submenuOn = '';
var mainMenu = '';

function overMenu(num)
	{
	if (num == menuOn || num == '')
		{
		return;
		}
	var img_name = 'pijl_' + num;
	document.images[img_name].src = pijl18x13.src;
	}

function outMenu(num)
	{
	if (num == menuOn || num == '')
		{
		return;
		}
	var img_name = 'pijl_' + num;
	document.images[img_name].src = niks18x13.src;	
	}

function clickMenu(menuName, submenuName)
	{
	if ( typeof(menuMapper[menuName]) != 'number' )
		{
		return;
		}

	var menuNum = menuMapper[menuName];

	// Als een ander submenu open is
	if ( submenuOn != '' && submenuOn != menuNum)
		{
		closeSubmenu(submenuOn);
		submenuOn = '';
		}

	// Heeft submenu, submenu openen
	if ( typeof(submenuMapper[menuName]) != 'undefined' )
		{
		openSubmenu(menuNum);
		submenuOn = menuNum;
		}

	// Submenu item is geklikt
	if ( submenuName != 'undefined' && typeof(submenuName) != 'undefined' )
		{
		var submenuNum = submenuMapper[menuName][submenuName];
		overMenu(submenuNum);
		var tmp = menuOn;
		menuOn = submenuNum;
		outMenu(tmp);
		}
	// Menu item is geklikt
	else
		{
		overMenu(menuNum);
		var tmp = menuOn;
		menuOn = menuNum;
		outMenu(tmp);
		}

	// Maak hoofdmenu weer wit en geselecteerde weer geel
	if ( mainMenu != menuName )
		{
		var domElement = getElement('menu_' + menuNum);
		domElement.className = 'menuSelect';
		if ( mainMenu != '' )
			{
			var num = menuMapper[mainMenu];
			domElement = getElement('menu_' + num);
			domElement.className = 'menuLink';
			}
		mainMenu = menuName;
		}
	}

function closeSubmenu(num)
	{
	var domElement = getElement('subMenu_' + num);
	domElement.style.display = 'none';
	}

function openSubmenu(num)
	{
	var domElement = getElement('subMenu_' + num);
	domElement.style.display = 'block';
	}

// get DOM Object
function getElement(elementId)
	{
	var element;
	if (document.getElementById)
		{
		element = document.getElementById(elementId);
		}
	else if (document.all)
		{
		element = document.all[elementId];
		}
	return element;
	}