function EL(id) {
	if (document.getElementById)
		return document.getElementById(id);
	else if (document.all)
		return document.all[id];
	else if (document.layers)
		return document.layers[id];
}


function on (obj) {
	obj.src = 'images/' + obj.id + '-1.gif';
}

function off (obj) {
	obj.src = 'images/' + obj.id + '-0.gif';
}

function changeImg(id, url) {
	EL(id).src = url;
}