function roll(rollUpImage, rollDownImage, imageElementId, elementId) {
	var element = document.getElementById(elementId);
	var image = document.getElementById(imageElementId);
	if (element.style.display == "none" || element.style.display == "") {
		element.style.display = "inline";
		image.src = rollUpImage;
	} else {
		element.style.display = "none";
		image.src = rollDownImage;
	}
}
function display(elementId) {
	var element = document.getElementById(elementId);
	if (element.style.display == "none" || element.style.display == "") {
		element.style.display = "inline";
	} else {
		element.style.display = "none";
	}
}