Lost Ajax Error Message

public function actionCreate()

{


	$model=new Addwithus;





	// Uncomment the following line if AJAX validation is needed


	// $this->performAjaxValidation($model);





	if(isset($_POST['Addwithus']))


	{


                


                    $rnd = rand(10,99999);  // generate random number between 0-9999


                    $model->attributes=$_POST['Addwithus'];


                    


                    $uploadedFile=CUploadedFile::getInstance($model,'pic');


                    $fileName = "{$rnd}-{$uploadedFile}";  // random number + file name


                    $model->pic = $fileName;


                   


                    


		if($model->save())


                        


                            $uploadedFile->saveAs(Yii::app()->basePath.'/../images/upload/'.$fileName); 


			$this->redirect(array('/site/thanks'));


	}


            


           


	$this->render('create',array(


		'model'=>$model,


               ));


}

When i user this image upload function then i lost AJAX error message could you tell what is the problem????