Viewing word documents in WPF

private void button1_Click(object sender, RoutedEventArgs e)
      {
          // Create OpenFileDialog
          Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();

          // Set filter for file extension and default file extension
          dlg.DefaultExt = ".txt";
          dlg.Filter = "Text documents (.txt)|*.txt";

          // Display OpenFileDialog by calling ShowDialog method
          Nullable<bool> result = dlg.ShowDialog();

          // Get the selected file name and display in a TextBox
          if (result == true)
          {
              // Open document
              string filename = dlg.FileName;
              FileNameTextBox.Text = filename;

              Paragraph paragraph = new Paragraph();
              paragraph.Inlines.Add(System.IO.File.ReadAllText(filename));
              FlowDocument document = new FlowDocument(paragraph);
              FlowDocReader.Document = document;
          }
      }