if (s1 == null && s2 == null) return 0; else if (s1 == null) return -1; else if (s2 == null) return 1;
    private int compareStrings(String s1, String s2)    {        int v = 0;        int result = (s1.toLowerCase()).compareTo(s2.toLowerCase());        if (result < 0) v = -1;        else if (result > 0) v = 1;        return v;    }