public function get_validation_error_message()
 {
     return StringVars::replace_vars($this->js_message, array('field1' => $this->first_field->get_label(), 'field2' => $this->second_field->get_label()));
 }
 public function get_js_validation(FormField $field)
 {
     return 'notEmptyFormFieldValidator(' . TextHelper::to_js_string($field->get_id()) . ', ' . TextHelper::to_js_string(StringVars::replace_vars($this->error_message, array('name' => strtolower($field->get_label())))) . ')';
 }