diff --git a/12/index.html b/12/index.html
index c8ab977..8762899 100644
--- a/12/index.html
+++ b/12/index.html
@@ -307,7 +307,7 @@
     
     
       var dragItem = document.querySelector("#shell_03header");
-    var container = document.querySelector("#shell03");
+    var container = document.querySelector("#shell_03");
 
     var active = false;
     var currentX;