$survey = Survey::retrieveSurvey($id); // retrieves the survey object structure
if ($survey == null || !$survey->isValid()) {
return $this->show_error($page, "Sondage ".$id." introuvable.", 'survey');
$survey = Survey::retrieveSurvey($id); // retrieves the survey object structure
if ($survey == null || !$survey->isValid()) {
return $this->show_error($page, "Sondage ".$id." introuvable.", 'survey');