I checked out the demo, it turns out this is for something reminiscent of frames rather than the main scrollbar. Just stop, don't have internal or nested scrol

I checked out the demo, it turns out this is for something reminiscent of frames rather than the main scrollbar. Just stop, don't have internal or nested scrollbars at all. Having part of the page scroll independently of the rest is a usability nightmare anyway, especially when you consider how it interacts with zooming.