boolean isZero(String s) {
            char[] cs = s.toCharArray();
            int base = ((cs.length > 1 && Character.toLowerCase(cs[1]) == 'x') ? 16 : 10);
            int i = ((base==16) ? 2 : 0);
            while (i < cs.length && (cs[i] == '0' || cs[i] == '.')) i++;
            return !(i < cs.length && (Character.digit(cs[i], base) > 0));
        }