C#: transcribe WAV file to text (speech-to-text) with System.Speech namespaces

How do you use the .NET speech namespace classes to convert audio in a WAV file to textual form which I can display on the screen or save to file?

I am looking for some tutorial samples.

UPDATE

Found a code sample here. But when I tried it it gives incorrect results. Below is the vb code sample I've adopted. (Actually I don't mind the lang as long as its either vb/c#...). It is not giving me proper results. I assume if we put the right grammar - i.e. the words we expect in the recording - we should get the textual output of that. First I've tried with sample words that are in the call. It sometimes printed only that (one) word and nothing else. Then I tried words which we totally do not expect in the recording...Unfortunately it printed out that too... :(

Imports System
Imports System.Speech.Recognition

Public Class Form1

    Dim WithEvents sre As SpeechRecognitionEngine

    Private Sub btnLiterate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLiterate.Click
        If TextBox1.Text.Trim.Length = 0 Then Exit Sub
        sre.SetInputToWaveFile(TextBox1.Text)
        Dim r As RecognitionResult
        r = sre.Recognize()
        If r Is Nothing Then
            TextBox2.Text = "Could not fetch result"
            Return
        End If
        TextBox2.Text = r.Text
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = String.Empty
        Dim dr As DialogResult
        dr = OpenFileDialog1.ShowDialog()
        If dr = Windows.Forms.DialogResult.OK Then
            If Not OpenFileDialog1.FileName.Contains("wav") Then
                MessageBox.Show("Incorrect file")
            Else
                Tex