--- a/core-javascript/tutorial.js	Wed Oct 26 16:42:59 2011 +0100
+++ b/core-javascript/tutorial.js	Wed Oct 26 17:22:34 2011 +0100
@@ -20,7 +20,7 @@
 // start closures
 TEST('closures', function()
 {
-
+    // A factory for creating get-set pairs.
     var get_set_factory = function(){
 
         var value;
@@ -37,8 +37,8 @@
         };        
     };
 
+    // Create and unpack two get-set pairs.
     var tmp;
-
     tmp= get_set_factory();
     var get_a = tmp.get;
     var set_a = tmp.set;
@@ -47,13 +47,16 @@
     var get_b = tmp.get;
     var set_b = tmp.set;
 
-
+    // Test that both pairs work.
     set_a(12);
     assert( get_a() === 12 );
 
     set_b(13);
     assert( get_b() === 13 );
 
+    // Test that each pair has its own value.
+    assert( get_a() === 12 );
+
 });
 // end closures