string inString = "LUXOR".ToLower();
 TextInfo cultInfo = new CultureInfo("en-US", false).TextInfo;
 string output = cultInfo.ToTitleCase(inString);

string inString = "LUXOR"
string outString = inString.Substring(0, 1).ToUpper() + inString.Substring(1).ToLower();

string inString = "LUXOR";
        string output = inString.Substring(0, 1) + inString.Substring(1).ToLower();

        string inString2 = "HI HOW ARE YOU";
        string[] finalstring = inString2.Split(' ');

        string output2 = string.Empty;
        foreach (var item in finalstring)
        {
            if (output2 == "")
            {
                output2 = (item.ToUpper().Substring(0, 1) + item.ToLower().Substring(1));
            }
            else
            {
                output2 += " " + (item.ToUpper().Substring(0, 1) + item.ToLower().Substring(1));
            }

        }