Convert String into Pascal Case in C#

private string ConvertToPascal(string strFileName)

    {

        if (strFileName == null) throw new ArgumentNullException("strException", "Null is not a valid string!");

        if (strFileName.Length == 0) return strFileName;

        string[] strWords = strFileName.Split(' ');

        for (int i = 0; i < strWords.Length; i++)

        {

            if (strWords[i].Length > 0)

            {

                string strWord = strWords[i];

                char strFirstLetter = char.ToUpper(strWord[0]);

                strWords[i] = strFirstLetter + strWord.Substring(1);

            }

        }

        return string.Join(" ", strWords);

    }