function actionExchangeRates()
{
$this->layout = '//layouts/none';
$coinbase = new Coinbase(Yii::app()->params['coinbase']['API_KEY']);
$exchange_rates = $coinbase->getExchangeRate();
header('Content-type: application/json');
echo CJSON::encode($exchange_rates);
Yii::app()->end();
}
