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");
	}
}

function swapImage(imageName, newImage) {
	if (document.images) {
		document[imageName].src = eval(newImage + ".src");
	}
}