how to display tamil letters inside textbox

hi i send the code to you if you i need any modifications then tell me

private void button1_Click(object sender, EventArgs e)
{
//RegisterNamibianCulture();
using (OpenFileDialog openFileDialog = new OpenFileDialog())
{

openFileDialog.Multiselect = false;
openFileDialog.Filter = "Wav audio file|*.wav";
openFileDialog.Title = "Open a Wav audio File";
if (openFileDialog.ShowDialog() == DialogResult.OK)
{
//System.Globalization.CultureInfo culture = new System.Globalization.CultureInfo("ta-IN");
//SpeechRecognitionEngine recognizer = new SpeechRecognitionEngine(culture );
recognizer.SetInputToWaveFile(openFileDialog.FileName);
recognizer.LoadGrammar(new DictationGrammar());

RecognitionResult Result = recognizer.Recognize();
if (Result != null)
{
foreach (RecognizedWordUnit Word in Result.Words)
{
//InputLanguage lang = GetArabicLang();
//if (lang == null)
// throw new NotSupportedException("tamil language keybord is not installed.");
////Set the current language of the system to
////the InputLanguage instance you need.
//InputLanguage.CurrentInputLanguage = lang;
//InputLanguage lan;
//richTextBox1.Text = Convert.ToString(Word.Text, System.Globalization.CultureInfo.CreateSpecificCulture("ta-IN"));
textBox1.Text = Convert .ToString (Word.Text,System.Globalization.CultureInfo.CreateSpecificCulture("ta-IN"));
listBox1.Items.Add(textBox1.Text);
}
}

}
}

no it's not a speech recoginsation. i am just talking in the microphone in tamil
and save it as a wave file and i just want to display that speech in textformat using richtextbox
which should be displayed using tamil letters