Both of these files should show a textarea with "true" or "false".

The right answer is "true".

The only difference between the two files is that the "window;" line is 
commented out in fail.html.  I assume this reference to window prevents some 
kind of optimization from happening, causing pass.html to work where fail.html 
doesn't.

$ diff pass.html fail.html
17c17
<   window; // it's magic!
---
>   //window; // it's magic!