Fix a typo and variable scope overlapping.

The fix was contributed by Pedro Algarvio (s0undt3ch) at
meineerde#2



git-svn-id: http://dev.holgerjust.de/svn/redmine-checkout/trunk@203 2c10314b-d60d-4f8f-b362-a6b3e82123ed

Author: meineerde

assets/javascripts/checkout.js

@@ -8,10 +8,10 @@ document.observe("dom:loaded", function() {
       });
       this.addClassName("selected")
 
-      var checkout_access = $('checkout_access');
-      if (checkout_access) {
-        var value = checkout_access.get(this.id);
-        checkout_acces.innerHTML = value;
+      var access = $('checkout_access');
+      if (access) {
+        var value = window.checkout_access.get(this.id);
+        access.innerHTML = value;
       }
 
       event.stop();