function visibleMenu(menu) {
	var m = document.getElementById(menu);
	m.style.display = 'block';
	return true;
}

function hideMenu(menu) {
	var m = document.getElementById(menu);
	m.style.display = 'none';
	return true;
}

function changeSelectedImage(img, id) {
	var image = document.getElementById(id);
	image.src=img;
}

function changeUnselectedImage(img, id) {
	var image = document.getElementById(id);
	image.src=img;
}