This page contains code that puts the vertical scrollbar of a long right side toggle menu at the exact position of the page's vertical scroll bar (if there's one). This takes away the ugliness of double scroll bars appearing next to each other when the menu (sliding into view from the right) would position itself immediately to the left of the window's scroll bar.
The css used to make this possible ensures that the html section functions as a wrapper for the body section in such a way that the window's vertical scrollbar is in fact the body's vertical scrollbar (no need to create a wrapper div to obtain this).
As the page's vertical scrollbar is now a 'body's bar', a menu button at the top (right) having something like
position: fixed; top: 1px; right: 3px; z-index: 999 would hide part of the page's vertical scrollbar (since the page's vertical scrollbar is not a 'html-bar' anymore), so javascript is required to make sure that the menu button moves to a position immediately to the left of the page's scrollbar (if there's one).
The script knows when the page has a vertical scrollbar and is able to calculate the scrollbar's different widths for the different browsers.
Make the window smaller until there's a vertical scrollbar and (1) watch the menu button gracefully position itself to the left of the scrollbar; (2) then open the menu and observe the menu's scrollbar (if there's one) position itself at the exact position of the page's scrollbar: no double scrollbars!
View the (commented) source of this page.