private boolean isValid(Node node) {
		if (node.x < 0 || node.y < 0 || node.x >= width || node.y >= height)
			return false;
		else {
			if (isInInvalidArray(node))
				return false;
			else {
				if (isInClosedArray(node))
					return false;
				else return true;
			}
		}
	}