Allow blank field (image upload)

Hi. I need to allow blank upload field in model.


public $logo;


public function rules()


		return array(

			array('manufacturer_name, 'required'),


                        array('logo', 'file', 'types'=>'jpg, gif, png'),




When I select and upload image, it works well, but I want to allow to leave empty upload field (in case that user don’t want to change logo).

Now empty field shows me error "[color=#555555][font=Arial, Helvetica, sans-serif]Logo cannot be blank.[/font][/color]". But logo is not in required rule…

array('logo', 'file', 'types' => 'jpg, gif, png', 'allowEmpty' => true)

Thank you!