diff --git a/12/dragable.js b/12/dragable.js
index 2345616..15ddf11 100644
--- a/12/dragable.js
+++ b/12/dragable.js
@@ -43,7 +43,7 @@
   }
 
   /*End dragging*/
-  dragObj.onmouseup = function(e) {
+  window.onmouseup = function(e) {
     if (dragObj) {
       dragObj = null;
       window.removeEventListener('mousemove', dragObject, true);
@@ -107,7 +107,7 @@ makeDragable('#shell_03header', '#shell_03')
   }
 
   /*End dragging*/
-  dragObj2.onmouseup = function(x) {
+  window.onmouseup = function(x) {
     if (dragObj2) {
       dragObj2 = null;
       window.removeEventListener('mousemove', dragObject2, true);