/* show/hide items on a diagram, hide items that are already visible */
function diagramPopup(item) {
	if(document.getElementById(item).className == 'visible')
	{
		document.getElementById(item).className = '';
	} else {
		hideItems ();
		showItem(item);
	}
}

/* show specified diagram item - called from diagramPopup() */
function showItem (item)
{
	var li = document.getElementById(item);
	li.className = 'visible';
}

/* hide all diagram items - called from diagramPopup() */
function hideItems () {
	var div = document.getElementById("diagram");
	var lis = div.getElementsByTagName("li");
	for (var i=0; i<lis.length; i++)
	{
		lis[i].className = '';
	}
}