//hide everything using getElementByTagName
//show or the one that was clicked on using getElementById

function changeDesc(targetId, classOf) {
	if (document.getElementById) {
		target = document.getElementById(targetId);
		for (i=0; i<document.getElementsByTagName("div" || "ul").length; i++)
		if (document.getElementsByTagName("div" || "ul").item(i).className == classOf) {
			document.getElementsByTagName("div" || "ul").item(i).style.display = "none";
		}
		if (target.style.display == "none") {
			target.style.display = "";
		}
	}
}
function badBrowser() {
	if (!document.getElementById) {
		document.write("<p>Your web browser does not support the W3C Document Object Model. As a result, features on this site which make use of the W3C DOM will be inaccessible to you. Please upgrade to a <a href='http://mozilla.org/products/firefox/'>standards-compliant web browser</a>.</p><hr />");
	}
}
badBrowser();