protected function addMultiSelecterElementToForm(Form $form, Property $property) {
		if ($this->toManyElement == $this::REF_MANY_ELEMENT_MULTISELECT) {
			$element = new Select($property->getName());
			$element->setAttribute('multiple', true);
		} else {
			$element = new MultiCheckbox($property->getName());
		}
		
		$options = $this->getValueOptionsFromEntity($property->getTargetEntity());
		if (empty($options)) {
			return false;
		}
		$element->setValueOptions($options);
		
		$element->setLabel($property->getName());
		$form->add($element);
	}