function switchDisplay(id) {
	var element = document.getElementById(id);
	var image = document.getElementById(id + "_image");

	if (element.style.display == "none")
	{
		element.style.display = "";
		if (image) image.src = "images/minus.gif";
	}
	else {
		element.style.display = "none";
		if (image) image.src = "images/plus.gif";
	}

	return false;
}