Client-side Javascript: Showing the browser's address bar when a site hides it?

Question

I'm trying to make a short client-side script that will run as UserJS in something like Greasemonkey. The script is to prevent sites from hiding the browser's navigation buttons. Topic info here.

I've come up with Window(location=yes, toolbar=yes, menubar=yes); This gives a "Read-Only" error though. All the info when I search is about web authors wanting to turn off the address bar (etc), not users wanting to turn it back on.

Click a product on this page to see the problem.