Come fo' ad aprire un documento docx in vb net

Ecco il codice:

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As _
       System.EventArgs) Handles MyBase.Load

        Button1.Text = "Browse"

        With OpenFileDialog1
            .Filter = "Office Documents " &
            "(*.doc, *.xls, *.ppt)|*.doc;*.xls;*.ppt"
            .FilterIndex = 1
        End With

    End Sub

    Private Sub Form1_Closing(ByVal sender As Object, ByVal e As _
       System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

        oDocument = Nothing

    End Sub

    Private Sub AxWebBrowser1_NavigateComplete2(ByVal sender As Object,
   ByVal e As axSHDocVw.DWebBrowserEvents2_NavigateComplete2Event) Handles WebBrowser1.

        On Error Resume Next

        If (oDocument <> Nothing) = True Then Exit Sub

        'Note: You can use the reference to the document object to
        '      automate the document server.
        MsgBox("File opened by: " & oDocument.Application.Name)

    End Sub

come potete aiutarmi

grazie