private Node findNode(Node node, int width, int height, int depth) {

			Node foundNode = null;
			if (node.used) {
				foundNode = findNode(node.right, width, height, ++depth);
				depth--;
				if (foundNode == null && depth == 0)
					foundNode = findNode(node.down, width, height, depth);
			} else if (width <= (this.width - node.x) && (height <= this.height - node.y)) {
				foundNode = node;
			}
			return foundNode;
		}