Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Cancel = True
MsgBox vbCrLf & UCase(Application.UserName) & vbCrLf & _
"Imposible guardar " & _
ActiveWorkbook.Name & " con un" & vbCrLf & _
"nombre distinto. El documento no se guardó.", _
Buttons:=vbCritical + vbOKOnly, Title:="¡ACCIÓN PROHIBIDA!"
End Sub