public function Item($ActivityID = 0) {
      $this->AddJsFile('activity.js');
      $this->Title(T('Activity Item'));

      if (!is_numeric($ActivityID) || $ActivityID < 0)
         $ActivityID = 0;
         
      $this->ActivityData = $this->ActivityModel->GetWhere(array('ActivityID' => $ActivityID));
      $this->SetData('Comments', $this->ActivityModel->GetComments(array($ActivityID)));
      $this->SetData('ActivityData', $this->ActivityData);
      
      $this->Render();
   }