private static Node getChildByTagNameNS(Node node, String ns, String tag) {
		if (node == null) return null;
		
		for (node = node.getFirstChild(); node != null; node = node.getNextSibling()) {
			
			if (node.getNodeType() != Node.ELEMENT_NODE) continue;

			if ((ns == null) && (node.getNamespaceURI() != null)) continue;

			if ((ns != null) && (! ns.equals(node.getNamespaceURI()))) continue;

			if (! tag.equals(node.getLocalName())) continue;

			return node;
		}

		return null;
	}