Private Sub TreeView1_MouseDown(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs) Handles TreeView1.MouseDown
  Dim tn As TreeNode = Me.TreeView1.GetNodeAt(e.X, e.Y)
  If tn Is Nothing Then Return 
  Select Case e.Node.Text
    Case "Media-Player"
      readmediaplayer()
    Case "Language/Sprache"
      Dim opti As New Optionen
      opti.Show()
    End Select
End Sub