Private Sub butFiledialog_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles butFiledialog.Click
        Dim strDatei As String
        With OpenFileDialog1
            Do
                .Filter = "Textdateien (*.txt)|*.txt|Alle Dateien (*.*)|*.*"
                .FilterIndex = 1
                .AddExtension = True
                .InitialDirectory = "C:\"
                .Title = "Please choose a text file"
                If .ShowDialog() = Windows.Forms.DialogResult.OK Then
                    strDatei = .FileName
                End If
            Loop Until .ShowDialog() = Windows.Forms.DialogResult.OK
        End With
    End Sub