public function ParsePostData()
 {
     // Check to see if this Control's Value was passed in via the POST data
     if (array_key_exists($this->strControlId, $_POST)) {
         parent::ParsePostData();
         $this->dttDateTime = new QDateTime($this->strText);
         if ($this->dttDateTime->IsNull()) {
             $this->dttDateTime = null;
         }
     }
 }