public function search()
{
$criteria = new CDbCriteria();
$criteria->compare('id', $this->id, true);
$criteria->compare('event_id', $this->event_id, true);
$criteria->compare('is_draft', $this->is_draft);
$criteria->compare('generated_document_id', $this->generated_document_id);
return new CActiveDataProvider(get_class($this), array('criteria' => $criteria));
}