public final static 
	String fixURLString(URL base, String u) {
		if (u == null) return null;
		if (u.endsWith("/"))
			u = u.substring(0, u.length()-1); // uniform "...com/" to "...com" address
		if (base == null && !u.contains(":/"))
			u = "http://"+u; // default protocol
		return u.toLowerCase();
	}