function sendToAddress($address, $amount)
{
    try {
        $amount = round($amount, 8);
        $bitcoin = new jsonRPCClient(kBitcoinURL);
        $txid = $bitcoin->sendtoaddress($address, floatval($amount));
        $log = new MessageLog('log', 255);
        $log->write("mywallet-bitcoin:{$address} BTC:{$amount} txid:{$txid}");
        return $txid;
    } catch (Exception $e) {
        return "Error: " . $e->getMessage();
    }
}