def capture(payment, creditcard, gateway_options)
      response = request(:capture_transaction, { 'Token' => security_token(gateway_options),
                                                 'RefNum' => payment.response_code,
                                                 'Amount' => payment.amount })
      billing_response response[:capture_transaction_response][:capture_transaction_return]
    end
def capture(payment, creditcard, gateway_options)
      response = request(:capture_transaction, { 'Token' => security_token(gateway_options),
                                                 'RefNum' => payment.response_code,
                                                 'Amount' => payment.amount })
      billing_response response[:capture_transaction_response][:capture_transaction_return]
    end
http://wiki.usaepay.com/developer/soap-1.4/methods/runcustomertransaction