public static string CapitalizeFirstLetter(string text) {
    if (text.Length < 2) {
        return text.ToUpper();
    }
    return Char.ToUpper(text[0]) + text.Substring(1).ToLower();
}

public static string CapitalizeEveryWord(string text) {
    var words = text.Split(' ');
    for (int n = 0; n < words.Length; n++) {
        words[n] = CapitalizeFirstLetter(words[n]);
    }
    return String.Join(" ", words);
}

public static string FormatFilename(string filename) {
    var words = filename.Split(' ');
    for (int n = 0; n < words.Length; n++) {
        string word = words[n];
        if (word.Length < 2) {
            words[n] = word.ToUpperInvariant();
        } else {
            words[n] = Char.ToUpperInvariant(word[0]) +
                word.Substring(1).ToLowerInvariant();
        }
    }
    return String.Join("_", words);
}