Also, perhaps it will make more sense for you to try it out:
Go there, and type in:
If you type
Password: I'm tired
it would try to include the file "blahI'm tired.js" - which won't work, because there is no such .js file.
So, all you need to create a .js file that is the combination of your username and password (no spaces!)... and then, edit that .js file just like the others...
I modified Borgtex's code slightly (just to make it XHTML compatible and clean it up a little bit), but you'll notice that if you open the "codingforums.js" file with notepad, you'll see this:
auth = true;
redirect = "http://www.codingforums.com/"
all you have to do at this point is change the redirect variable to the page you want to redirect to.