Public Sub LoadDocument(ByVal filename As String)
   ' ...
   ' benötigte Variablen deklarieren
   Dim fstream As FileStream
   Dim reader As StreamReader
   Try
      ' Stream und Reader erstellen
      fstream = New FileStream(filename, ileMode.Open, _
      FileAccess.Read,FileShare.Read)
      reader = New StreamReader(fstream, Encoding.Unicode)
      ' Lesen
      ' ...
   Catch ex As SecurityException
      ' ...
   Finally
      ' Resourcen freigeben
      If reader IsNot Nothing Then reader.Close()
      If fstream IsNot Nothing Then fstream.Close()
   End Try
End Sub

Ralf