You will need to use index-nolayout.html.
This file is located in your deployment\web folder. The nolayout.html will make sure the scrollbar is positioned on the browser instead of the content.
Goto index.html and play around with the divs in the bordercontainer.
What happens if you remove the "menu 2" div. Seems like you need to reassign the order of your divs in the main content container. You could set the main content div and the menu 2 in a new div and then you could reposition by floating and playing with the overflow property.