diff --git a/security-attack/send.js b/security-attack/send.js
index 766e67e..8cc5902 100644
--- a/security-attack/send.js
+++ b/security-attack/send.js
@@ -1,5 +1,5 @@
 function mkSend(rawSend) {
-  var whiteList = { "http://www.microsoft.com/mail": true,
+  let whiteList = { "http://www.microsoft.com/mail": true,
                     "http://www.microsoft.com/owa" : true };
   function newSend (target, msg) {
     if (whiteList[target]) {
diff --git a/verification/avl/avl.js b/verification/avl/avl.js
index 59f3362..e945856 100644
--- a/verification/avl/avl.js
+++ b/verification/avl/avl.js
@@ -5,7 +5,7 @@
 
 function make_node(v)
 {
-  var node = {
+  let node = {
     value  : v,
     height : 1,
     left   : null,
@@ -150,15 +150,3 @@ function remove(v, t)
 
 // Test
 
-// function Test() {
-//   var avl = null; console.log(avl);
-//   avl = insert(1,avl); console.log(avl);
-//   avl = insert(2,avl); console.log(avl);
-//   avl = insert(3,avl); console.log(avl);
-//   console.log(find(1,avl));
-//   console.log(find(2,avl));
-//   console.log(find(3,avl));
-//   console.log(find(4,avl));
-//   avl = remove(2,avl); console.log(avl);
-// }
-// Test();