diff --git a/session/users.go b/session/users.go
index b61fd9e..471b799 100644
--- a/session/users.go
+++ b/session/users.go
@@ -172,10 +172,8 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// non-GET request as login request
-
-	succ := true
-	data := map[string]interface{}{"succ": &succ}
-	defer util.RetJSON(w, r, data)
+	result := util.NewResult()
+	defer util.RetResult(w, r, result)
 
 	args := struct {
 		Username string
@@ -185,16 +183,16 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	args.Username = r.FormValue("username")
 	args.Password = r.FormValue("password")
 
-	succ = false
+	result.Succ = false
 	for _, user := range conf.Users {
 		if user.Name == args.Username && user.Password == conf.Salt(args.Password, user.Salt) {
-			succ = true
+			result.Succ = true
 
 			break
 		}
 	}
 
-	if !succ {
+	if !result.Succ {
 		return
 	}
 
diff --git a/util/ret.go b/util/ret.go
index 84f69a4..488dc91 100644
--- a/util/ret.go
+++ b/util/ret.go
@@ -26,6 +26,37 @@ import (
 // Logger.
 var retLogger = log.NewLogger(os.Stdout)
 
+// Result.
+type Result struct {
+	Succ bool        `json:"succ"` // successful or not
+	Code string      `json:"code"` // return code
+	Msg  string      `json:"msg"`  // message
+	Data interface{} `json:"data"` // data object
+}
+
+// NewResult creates a result with Succ=true, Code="0", Msg="", Data=nil.
+func NewResult() *Result {
+	return &Result{
+		Succ: true,
+		Code: "0",
+		Msg:  "",
+		Data: nil,
+	}
+}
+
+// RetResult writes HTTP response with "Content-Type, application/json".
+func RetResult(w http.ResponseWriter, r *http.Request, res *Result) {
+	w.Header().Set("Content-Type", "application/json")
+
+	data, err := json.Marshal(res)
+	if err != nil {
+		retLogger.Error(err)
+		return
+	}
+
+	w.Write(data)
+}
+
 // RetJSON writes HTTP response with "Content-Type, application/json".
 func RetJSON(w http.ResponseWriter, r *http.Request, res map[string]interface{}) {
 	w.Header().Set("Content-Type", "application/json")