function setupAcronyms () {
	var acronyms = document.getElementsByTagName('acronym');
	for (var i=0; i<acronyms.length; i++) {
		addEvent(acronyms[i], "click", toggleAcronym);
	}
}
function toggleAcronym (e) {
	var element = getEventSrc(e);
	var elementText = element.firstChild.nodeValue;
	var elementTitle = element.getAttribute('title');
	// replace the acronym text with its title
	element.firstChild.nodeValue = elementTitle;
	element.setAttribute('title', elementText);
}

function addEvent(objObject, strEventName, fnHandler) { 
	// DOM-compliant way to add an event listener 
	if (objObject.addEventListener) 
		objObject.addEventListener(strEventName, fnHandler, false); 
	// IE/windows way to add an event listener 
	else if (objObject.attachEvent) 
		objObject.attachEvent("on" + strEventName, fnHandler); 
}
function getEventSrc(e) { 
	// get a reference to the IE/windows event object 
	if (!e) e = window.event; 
	// DOM-compliant name of event source property 
	if (e.target) 
		return e. target; 
	// IE/windows name of event source property 
	else if (e.srcElement)
		return e.srcElement; 
}
addEvent(window, "load", setupAcronyms);