patch for com_tienda currency helper getExchangeRateYahoo()

function getExchangeRateYahoo( $currencyFrom, $currencyTo)
    {
        static $has_run;

        // if refresh = true
        // query yahoo for exchange rate
        if (!empty($has_run)) { sleep(1); }

        //$url = "http://quote.yahoo.com/d/quotes.csv?s={$currencyFrom}{$currencyTo}=X&f=l1&e=.csv";



        // $handle = @fopen($url, 'r');

        // if ($handle) {
            // $result = fgets($handle, 4096);
            // fclose($handle);
        // }
        /*
Display current exchange rate requested by user.

Copyleft ak47suk1(http://kaibathelegacy.blogspot.com)
*/

        $exchange_rates = json_decode(file_get_contents("http://openexchangerates.org/latest.json"));

        $result=$exchange_rates->rates->$currencyTo/$exchange_rates->rates->$currencyFrom;

        $rate = (float) $result * 1.0;

        $has_run = true;

        return $rate;
    }