javascript prototyping: why doesn't this work?
<p>I'm looking at trying the following code:</p>

<pre><code>var classA = function() {};
classA.prototype = { x: 4, y: 6 };
classA.prototype.prototype = { z: 10 };
var foo = new classA();
alert(foo.z);
</code></pre>

<p>Why does the alert come back as undefined?  Shouldn't javascript follow the prototype chain to find z?</p>
