I doubt if this is possible using JavaScript. This would definitely hinder the user ... who would want a site that would lock the browser.
If you want the browser to be dedicated to one website only, I suggest that you check out Prism:
http://prism.mozilla.com/
The stand-alone version is essentialy a mini-browser that locks the user to one website by making the addres bar read-only.
Please mark my reply as an
answer if it helps you.
Check out my blog