[bazsouthafrica]

This is exactly the catch with respect to function invocation method that I was trying to point out. It seems that in a call back method, `this` gets bound to the global object. I suspect it is because it is called with the same mechanism that is used for function invocation. That being said, I did not use this example because one needs to implement a callback to see the error. My example that I chose in my article was designed so that anyone could just create the JavaScript, fire it up in a browser, and see the error for themselves.

I do however intend to use an example similar to the one you have presented when I cover closures and scoping in JavaScript.