ulong reply = show_dialog (dialog, &dlg),
{
  dlg = {
          show_mode : DLG_OVERLAY,
          dialog_proc : question_dlg_proc,
          parameters : {
                         STR_TITLE,
                         STR_MESSAGE,
                         STR_OPTION_1,
                         STR_OPTION_2,
                         STR_OPTION_3
                       }
        }
};

select (reply)
{
  ...
}