compilation bug fix

db.go

 }
 
 func (m *TransactionDB) addRpnOut(r RpnReq) error {
-
+	return nil
 }
 
-func (m *TransactionDB) updateRpnOutNameAndCard(orderid string, signature string, name string, card string) error {
-
+func (m *TransactionDB) updateRpnOutNameAndCard(orderid string, signature string, name string, card string) (row RpnReq, err error) {
+	err = nil
+	row = RpnReq{}
+	return
 }

rpn.go

 package main
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
 	return s
 }
 
+func retrieveFormValue(form url.Values, key string) (r string, err error) {
+
+	if _, ok := form[key]; ok {
+		r = form[key][0]
+		err = nil
+	} else {
+		r = ""
+		err = errors.New("Key [" + key + "] not found in HTTP request")
+	}
+	return r, err
+}
+
 //receive RPN user name and card number
 func rpnNameAndCard(w http.ResponseWriter, r *http.Request) {
 	if r.Method != "POST" {
 		return
 	}
 	r.ParseForm()
-	order_id, ok1 := r.Form["id"][0]
-	signature, ok2 := r.Form["si"][0]
-	user_name, ok3 := r.Form["name"][0]
-	user_card, ok4 := r.Form["card"][0]
+	order_id, ok1 := retrieveFormValue(r.Form, "id")
+	signature, ok2 := retrieveFormValue(r.Form, "si")
+	user_name, ok3 := retrieveFormValue(r.Form, "name")
+	user_card, ok4 := retrieveFormValue(r.Form, "card")
 
-	if !(ok1 && ok2 && ok3 && ok4) {
+	if !(ok1 == nil && ok2 == nil && ok3 == nil && ok4 == nil) {
 		fmt.Fprintf(w, "missing parameters")
 		return
 	}