Private Sub txtEnclosureAttached_Change()
Dim Rng As Range
Set Rng = ActiveDocument.Bookmarks(""bmkEnclosureAttached"").Range
With Rng
  .Text = Replace(Enclosures.Text, vbcr, ", ")
  Application.ScreenRefresh
End With 
ActiveDocument.Bookmarks.Add ""bmkEnclosureAttached"", Rng 
End Sub