private void readFile()
        {
            var query = File.ReadLines(openFileDialog1.FileName).Where(line => !String.IsNullOrEmpty(line))
                                        .GroupBy(line => line.First());
            charFreq();
        }

        private void charFreq()
        {
            var charFreq =
                from c in line.ToCharArray()
                group c by c into groupFrequencies
                select groupFrequencies;

            foreach (var c in charFreq)
                rTxtOutput.Text += (String.Format("{0} : {1}", c.Key, c.Count())) + "\r\n";
        }