/**
  * Returns the data model based on the primary key given in the GET variable.
  * If the data model is not found, an HTTP exception will be raised.
  */
 public function loadModel()
 {
     if ($this->_model === null) {
         if (isset($_GET['id'])) {
             $this->_model = Corredor::model()->findbyPk($_GET['id']);
         }
         if ($this->_model === null) {
             throw new CHttpException(404, 'The requested page does not exist.');
         }
     }
     return $this->_model;
 }