为phpyiiframework上传新图像时，从文件夹中删除图像

我对php yiiframework很陌生。我有一个用户模型，它会获取用户的基本信息，包括个人资料图像，但当我更新个人资料的新图像时，我必须删除图像文件。我使用以下方法上传了文件。

public function actionUpdate()
    {
        $model=$this->loadModel($id);    
        $random = substr(number_format(time() * rand(),0,'',''),0,10);          
        if(isset($_POST['Users']))
        {                           
            $model->attributes=$_POST['Users'];             
            $uploadedFile=CUploadedFile::getInstance($model,'image_path');
            $fileName = $milliseconds. '-' .$random;
            $model->image_path = $fileName;
            if($model->save())              
                $uploadedFile->saveAs(Yii::app()->basePath.'/../images/uploaded/'.$fileName);
                $this->redirect(array('view','id'=>$model->id));
        }    
        $data = PanXCore::getDataForCreateUser();
        $userRoles = new UserRoles();
        $this->render('create',array(
            'model'=>$model,
                'roles' => $data['roles'],
                'userRoles' => $userRoles               
        ));
    }