protected function setSubmitName(string $parentSubmitName): void
  {
    $submitKey = $this->submitKey();

    if ($parentSubmitName!=='')
    {
      if ($submitKey!=='') $this->submitName = $parentSubmitName.'['.$submitKey.']';
      else                 $this->submitName = $parentSubmitName;
    }
    else
    {
      $this->submitName = $submitKey;
    }
  }