I have the cookies and session settings working OK, and abstracted to a little module, so that will be handy in future. I also have the widget controls on the page working, and retaining the correct settings. Now the problem is that I'm trying to turn stylesheets on and off using their "disabled" property, but it's really not working at all. Both Firefox and Chrome have problems, but they exhibit different behaviour. The spec says I can write to the disabled attribute, but it doesn't seem to work on Chrome if the stylesheet was disabled initially in the HTML code; with Firefox, the first disabled stylesheet seems to be active when the page first loads. Frustrating and annoying. I may have to resort to deleting and inserting link elements in the header, which is very crude, but might actually work.