diff --git a/checksum.go b/checksum.go
index 09b55c8..874827c 100644
--- a/checksum.go
+++ b/checksum.go
@@ -4,6 +4,7 @@ import (
 	"crypto/md5"
 	"fmt"
 	"io"
+	"net/url"
 )
 
 func md5str(s string) string {
@@ -11,3 +12,41 @@ func md5str(s string) string {
 	io.WriteString(h, s)
 	return fmt.Sprintf("%x", h.Sum(nil))
 }
+
+func md5LeanworkForm(form url.Values) string {
+	s := ""
+	if _, ok := form["pickupUrl"]; ok {
+		s += form["pickupUrl"][0]
+		s += form["receiveUrl"][0]
+		s += form["signType"][0]
+		s += form["orderNo"][0]
+		s += form["orderAmount"][0]
+		s += form["orderCurrency"][0]
+		s += form["customerId"][0]
+		s += md5key
+	}
+	return md5str(s)
+}
+
+func isLeanworkFormValid(form url.Values) bool {
+	r := md5LeanworkForm(form)
+	sign := form["sign"][0]
+	return r == sign
+}
+
+func md5RpnForm(form url.Values) string {
+	s := ""
+	if _, ok := form["version"]; ok {
+		s += "sign_type=" + form["sign_type"][0] + "|"
+		s += "mid=" + form["mid"][0] + "|"
+		s += "notify_url=" + form["notify_url"][0] + "|"
+		s += "order_id=" + form["order_id"][0] + "|"
+		s += "order_amount=" + form["order_amount"][0] + "|"
+		s += "order_time=" + form["order_time"][0] + "|"
+		s += "user_id=" + form["user_id"][0] + "|"
+		s += "user_name=" + form["user_name"][0] + "|"
+		s += "user_cardno=" + form["user_cardno"][0] + "|"
+		s += "key=" + md5key
+	}
+	return md5str(s)
+}
diff --git a/checksum_test.go b/checksum_test.go
index eb90ec4..d106639 100644
--- a/checksum_test.go
+++ b/checksum_test.go
@@ -16,7 +16,7 @@ func TestMD5Sum(t *testing.T) {
 	t.Errorf("something is wrong %d ", 1)
 }
 
-func TestRequestForm(t *testing.T) {
+func buildForm() url.Values {
 	// receiveUrl= [http://publicapi.lwork.com:8080/notify/default_notify]
 	// orderAmount= [1200]
 	// customerId= [123]
@@ -36,6 +36,11 @@ func TestRequestForm(t *testing.T) {
 	form.Add("orderCurrency", "CNY")
 	form.Add("customerId", "123")
 	form.Add("sign", "06bcbd40cf6b914ef8ea6596730571ba")
+	return form
+}
+
+func TestRequestForm(t *testing.T) {
+	form := buildForm()
 
 	md5key := "492815086935204"
 	expected := "06bcbd40cf6b914ef8ea6596730571ba"
@@ -54,3 +59,13 @@ func TestRequestForm(t *testing.T) {
 	assert := assert.New(t)
 	assert.Equal(expected, md5str(s), "the md5 result should be equal")
 }
+
+func TestMd5Form(t *testing.T) {
+	form := buildForm()
+	expected := "06bcbd40cf6b914ef8ea6596730571ba"
+	expectedkey := "492815086935204"
+	assert := assert.New(t)
+	assert.Equal(expectedkey, md5key, "md5key should be 492815086935204")
+	result := md5LeanworkForm(form)
+	assert.Equal(expected, result, "expected signature should be equal")
+}
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..4df84af
--- /dev/null
+++ b/config.go
@@ -0,0 +1,44 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+)
+
+type AppConfig struct {
+	Rpn struct {
+		Url     string `json:Url`
+		UrlTest string `json:UrlTest`
+		MD5P2P  string `json:MD5P2P`
+		MD5FAT  string `json:MD5FAT`
+	} `json:Rpn`
+	LeanWork struct {
+		MD5Key string `json:MD5Key`
+	} `json:LeanWork`
+}
+
+var Config AppConfig
+
+func readConfig() error {
+	log.Printf("Read configration from config.json")
+	body, err := ioutil.ReadFile("config.json")
+	if err != nil {
+		log.Fatal("Fatal error Cannot read config ..")
+		return err
+	}
+	err = json.Unmarshal(body, &Config)
+	if err != nil {
+		log.Fatal("cannot read config into json")
+		return err
+	}
+
+	j, err := json.MarshalIndent(Config, "", "\t")
+	if err != nil {
+		log.Fatal("cannot print back to json")
+		return err
+	}
+	fmt.Println(string(j))
+	return err
+}
diff --git a/config.json b/config.json
new file mode 100644
index 0000000..166eeb9
--- /dev/null
+++ b/config.json
@@ -0,0 +1,11 @@
+{
+    "Rpn": {
+         "Url" : "https://deposit.paylomo.net/pay.php?r=payEasy",
+         "UrlTest" : "https://deposit-mac.chinapaytech.com/pay.php?r=payEasy",
+         "MD5P2P"   : "370296119874502",
+         "MD5FAT"   : "207841502473198"
+    },
+    "LeanWork" :{
+         "MD5Key"   :  "492815086935204" 
+    }
+}
\ No newline at end of file
diff --git a/main.go b/main.go
index 75a9a07..35043a3 100644
--- a/main.go
+++ b/main.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"crypto/md5"
 	"database/sql"
 	"fmt"
 	"html/template"
@@ -158,31 +157,28 @@ func StartPay(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprintf(w, "fuck")
 		return
 	}
-	s := ""
 	r.ParseForm()
 
+	if !isLeanworkFormValid(r.Form) {
+		fmt.Fprintf(w, "invalid request")
+		return
+	}
+
 	for key, value := range r.Form {
 		fmt.Printf("%s= %s\n", key, value)
 		fmt.Fprintf(w, "%s= %s\n", key, value)
 	}
-	if _, ok := r.Form["pickupUrl"]; ok {
-		s += r.Form["pickupUrl"][0]
-		s += r.Form["receiveUrl"][0]
-		s += r.Form["signType"][0]
-		s += r.Form["orderNo"][0]
-		s += r.Form["orderAmount"][0]
-		s += r.Form["orderCurrency"][0]
-		s += r.Form["customerId"][0]
-		s += md5key
-	}
-	//var h = md5.New()
-	data := []byte(s)
-	fmt.Printf("my md5=%x", md5.Sum(data))
-	fmt.Fprintf(w, "my md5=%x", md5.Sum(data))
+	sign := md5LeanworkForm(r.Form)
+
+	fmt.Printf("my md5=%s, valid = %t", sign, isLeanworkFormValid(r.Form))
+	fmt.Fprintf(w, "my md5=%s", sign)
 
 }
 
 func main() {
+	readConfig()
+	return
+
 	log.Println("Server started on: http://localhost:8080")
 	http.HandleFunc("/", StartPay)
 	//http.HandleFunc("/", Index)
diff --git a/rpn.go b/rpn.go
new file mode 100644
index 0000000..aa04f85
--- /dev/null
+++ b/rpn.go
@@ -0,0 +1,13 @@
+package main
+
+import "net/url"
+
+// var url = "https://deposit.paylomo.net/pay.php?r=payEasy"          //production
+// var url = "https://deposit-mac.chinapaytech.com/pay.php?r=payEasy" //test
+// var md5p2p = "370296119874502"
+// var md5fat = "207841502473198"
+
+//send request to RPN to initiate transaction
+func sendReq(form url.Values) {
+
+}