function getElementsWithClass(tag,classname){
	
	var arrRet = new Array();
	var e = 0;

	for (i = 0; i < document.getElementsByTagName(tag).length; i++) {

		if (document.getElementsByTagName(tag)[i].className == classname) {
		
			arrRet[e] = document.getElementsByTagName(tag)[i];
			e++;

		}

	}

	return arrRet;

}

var lastOpen;

function toggleMenu(id) {

	if (lastOpen != id && lastOpen == null) {

		document.getElementById(id).src = 'images/' + id + '-on.jpg'

		for (a = 0; a < getElementsWithClass('li', id).length; a++) {

			getElementsWithClass('li', id)[a].style.display = 'block';

		}

	} else {

		document.getElementById(lastOpen).src = 'images/' + lastOpen + '-off.jpg'
		document.getElementById(id).src = 'images/' + id + '-on.jpg'

		for (a = 0; a < getElementsWithClass('li', lastOpen).length; a++) {

			getElementsWithClass('li', lastOpen)[a].style.display = 'none';

		}

		for (a = 0; a < getElementsWithClass('li', id).length; a++) {

			getElementsWithClass('li', id)[a].style.display = 'block';

		}

	}

	lastOpen = id;

}

var lastOpenMap = 'overheid';

function toggleMap(id) {

	if (lastOpenMap != id && lastOpenMap == null) {

		document.getElementById('img_' + id).src = 'images/' + id + '-on.jpg'
		document.getElementById(id).style.display = 'block';

	} else {

		document.getElementById('img_' + lastOpenMap).src = 'images/' + lastOpenMap + '-off.jpg'
		document.getElementById('img_' + id).src = 'images/' + id + '-on.jpg'

		document.getElementById(lastOpenMap).style.display = 'none';
		document.getElementById(id).style.display          = 'block';

	}

	lastOpenMap = id;

}