method cvs_tag_selected_files =
      match selection with
        [] ->
          ()
      |        l ->
          let files = List.map (fun t -> (behav#cvs_info_of_t t).Ocvs_types.cvs_file) l in
         (* ask for confirmation *)
          match GToolbox.input_string
              Ocvs_messages.m_tag_files
              (Ocvs_messages.enter_tag_for_files files)
          with
            Some tag ->
              (
               let confirm s =
                 (GToolbox.question_box ~title: Ocvs_messages.mConfirm
                    ~buttons: [ Ocvs_messages.mYes ; Ocvs_messages.mNo ]
                   s) = 1
               in
               try behav#cvs_tag_files confirm tag files
               with Failure s -> GToolbox.message_box Ocvs_messages.error s
              )
          | None ->
              ()