function updateMapNode(mapNode) {


	var name = "node" + mapNode;
//	alert('update ' + name);	
	
	var el = document.getElementById(name);
	el.style.display = 'block'

	var img = document.getElementById("image" + mapNode);
	img.src = 'images/maplogo_circle.gif';


	for (var n = 1; n <= 6; n++) {

		if (n != mapNode) {
			// update branch panels
			el = document.getElementById("node" + n);
			el.style.display = 'none';
			
			
			// update node image
			img = document.getElementById("image" + n);
			img.src = 'images/maplogo.gif';
			
		}
			
	}




}