private function loadCardDetailsModel($id=NULL)
	{
		if ($id == NULL)
			throw new CHttpException(400, Yii::t('Api.card', 'Missing card ID'));

		$model = UserMetadata::model()->getPrototype('UserMetadata', array(
		             'user_id' => $this->user->id,
		             'key' => $id.'_card_settings'
		         ), array('value' => '{}'));

		$model->value = CJSON::decode($model->value);

		return $model;
	}