function toggleImage(image) {
	if (typeof image == "string") {
		image = document.getElementById(image);
	}
	var src = image.src;
	var index = src.lastIndexOf(".");
	if (src.indexOf("-off") == -1) {
		src = src.substring(0, index) + "-off" + src.substring(index);
	} else {
		src = src.substring(0, index - 4) + src.substring(index);
	}
	image.src = src;
}