Private Sub btnAddRec_Click()
    Refresh
    With CodeContextObject
    On Error Resume Next
    DoCmd.GoToRecord , , acNewRec
    If Err.Number <> 0 Then
    btnAddRec.Enabled = False
    End If
    End With
End Sub

Private Sub btnAddRec_Click()
On Error GoTo Err1
  DoCmd.GoToRecord , , acNewRec
  Exit Sub
Err1:
  Description.SetFocus
  btnAddRec.Enabled = False
  MsgBox (Err.Description)

End Sub