// JavaScript Document
function toggleButton(btn, nr, on) {
	var buttonL = document.getElementById("buttonL" + btn);
	var buttonR = document.getElementById("buttonR" + btn);
	buttonL.src = (on ? 'img/button'+nr+'left.gif' : 'img/spacer.gif');
	buttonR.src = (on ? 'img/button'+nr+'right.gif' : 'img/spacer.gif');
}