I am trying to use this code snippet to get the selected text in outlook 2003

Sub SelectedTextDispaly()

    On Error Resume Next
      Err.Clear

      Dim oText As TextRange

      ''# Get an object reference to the selected text range.
      Set oText = ActiveWindow.Selection.TextRange

      ''# Check to see whether error occurred when getting text object
      ''# reference.
      If Err.Number <> 0 Then

         MsgBox "Invalid Selection. Please highlight some text " _
            & "or select a text frame and run the macro again.", _
            vbExclamation
         End

      End If

      ''# Display the selected text in a message box.
      If oText.Text = "" Then
         MsgBox "No Text Selected.", vbInformation
      Else
         MsgBox oText.Text, vbInformation
      End If

End Sub

When running this macro I get the error

---------------------------
Microsoft Visual Basic
---------------------------
Compile error:

User-defined type not defined

Do I need to add any references to fix this up?