I'm trying to follow the very similar request in this thread

/showthread.php?43155-Macro-for-sending-emails-to-give-classification-prefix-options-to-the-subject-line

but pasting the below code into ThisOutlookSession in VBA results in nothing occuring

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)

  Dim frm As UserForm1
  Dim chosenvalue As String


  Set frm = New UserForm1


  frm.Show vbModal


  Select Case True
  Case frm.OptionButton1.Value
    chosenvalue = "PERSONAL"
  Case frm.OptionButton2.Value
    chosenvalue = "UNCLASSIFIED"
  Case frm.OptionButton3.Value
    chosenvalue = "CLASSIFIED"
  Case Else  ' no value chosen
    MsgBox "you did not select a value. cancelling send."
    Cancel = True
    Exit Sub
  End Select


  If TypeName(Item) = "MailItem" Then
    Item.Subject = Item.Subject & " [SEC=" & chosenvalue & "]"
  End If


End Sub
Am I missing something obvious?