diff --git a/main.go b/main.go
index 1d1eed2..b399925 100644
--- a/main.go
+++ b/main.go
@@ -9,45 +9,44 @@ import (
 func main() {
 	var fi, fo string
 	flag.Usage = func() {
-		fmt.Println("json2nats version v0.1")
+		fmt.Println("json2nats version v0.2")
 		flag.PrintDefaults()
 	}
 	flag.StringVar(&fi, "i", "default.json", "Json file name")
 	flag.StringVar(&fo, "o", "", "Output file name")
 	flag.Parse()
 
-	b, err := os.ReadFile(fi)
+	bi, err := os.ReadFile(fi)
 	if err != nil {
 		panic(err)
 	}
 	fmt.Println("[OK] Read json file:", fi)
 
-	var stri, stro string
-	stri = string(b)
-	for i := range stri {
-		switch stri[i] {
+	var bo []byte = make([]byte, 0)
+	for i := range bi {
+		switch bi[i] {
 		case ' ':
 		case '\n':
 		case '\r':
 			// do nothing.
 		case '"':
-			stro += `\"`
+			bo = append(bo, []byte(`\"`)...)
 		case ',':
-			stro += `, `
+			bo = append(bo, []byte(`, `)...)
 		default:
-			stro += string(stri[i])
+			bo = append(bo, bi[i])
 		}
 	}
 
 	fmt.Println("[OK] Make nats tool string:")
 
 	if fo != "" {
-		err = os.WriteFile(fo, []byte(stro), 0644)
+		err = os.WriteFile(fo, bo, 0644)
 		if err != nil {
 			panic(err)
 		}
 		fmt.Println("[OK] Write to:", fo)
 	}
 
-	fmt.Println(stro)
+	fmt.Println(string(bo))
 }