function swapImage(elementId, newImage) {
	document.getElementById(elementId).src = newImage;
}

function addClass(elementId, className) {
	//call a built-in prototype.js function to add a style sheet class to an element
	Element.classNames(elementId).add(className);
}
function removeClass(elementId, className) {
	//call a built-in prototype.js function to remove a style sheet class from an element
	Element.classNames(elementId).remove(className);
}
function loadPage(elId, pageUrl) {
	new Ajax.Updater(elId, pageUrl, { method:'get' });
}