protected function getStdEditControl($readOnly = false)
 {
     $control = new InputDateControl(null, $this->name);
     $control->setValue($this->toString());
     $control->setReadOnly($readOnly);
     if ($this->validation != '') {
         $control->addCssClass($this->validation);
     }
     return $control;
 }
 /**
  * @inheritdoc
  */
 public function toJavascript()
 {
     return $this->datumvon->toJavascript() . $this->datumbis->toJavascript();
 }