diff --git a/README.md b/README.md
index d1577a8..18d68c2 100644
--- a/README.md
+++ b/README.md
@@ -23,13 +23,13 @@ func main(){
   t := reflect.TypeOf(m)
   for i := 0; i < t.NumField(); i++ {
   
-    widget:=tagfast.Tag(m,i,"form_widget")
+    widget:=tagfast.Tag(t,i,"form_widget")
     fmt.Println("widget:",widget)
     
-    valid:=tagfast.Tag(m,i,"valid")
+    valid:=tagfast.Tag(t,i,"valid")
     fmt.Println("valid:",valid)
     
-    xorm:=tagfast.Tag(m,i,"xorm")
+    xorm:=tagfast.Tag(t,i,"xorm")
     fmt.Println("xorm:",xorm)
     
   }
diff --git a/tagfast.go b/tagfast.go
index 63994e3..e02ec1c 100644
--- a/tagfast.go
+++ b/tagfast.go
@@ -31,9 +31,8 @@ func GetTag(struct_name string, field_name string) (r TagFast, ok bool) {
 	return
 }
 
-//usage: Tag(m,i,"form")
-func Tag(i_struct interface{}, field_no int, key string) (tag string) {
-	t := reflect.TypeOf(i_struct)
+//usage: Tag(t, i, "form")
+func Tag(t reflect.Type, field_no int, key string) (tag string) {
 	if t.Field(field_no).Tag == "" {
 		return ""
 	}