function toggleLayer(whichLayer) {
	if (document.getElementById) {
		var style2 = document.getElementById(whichLayer).style;
	}
	style2.display = style2.display? "":"none";
}

function turnOn(imageName) {
	if (document.images) {
		document[imageName].src = eval(imageName + "on.src");
	}
}

function turnOff(imageName) {
	if (document.images) {
		document[imageName].src = eval(imageName + "off.src");
	}
}