var lastOpened = '';

function hideLast() {
	if (lastOpened!='') {
	document.getElementById(lastOpened).style.display = 'none';
	}
}

function showhideElement(id) {
	hideLast();
	if ((document.getElementById(id))&&(id!=lastOpened)) {
		var thisEl = document.getElementById(id);
		if (thisEl.style.display!='block') {
			thisEl.style.display = 'block';
			lastOpened = id;
		}
	} else if (document.getElementById(id)) { lastOpened=''; }

}