This is just a CSS setting. On the MSDN site, the tree navigation list
is contained within a div that has its overflow set to auto.

http://www.w3schools.com/Css/pr_pos_overflow.asp

" overflow: auto - If the content is clipped, the browser should
display a scroll-bar to see the rest of the content"

Setting focus requires some custom JavaScript, which you can do with AJAX,
but you will have to write it. Mick already has the scrollbar portion solved
for you.

As for your original question, I am in agreement with Eliyahu. Use skins and
then assign the ID. Watch this carefully, however, as you can completely
cluster the application if you are pulling looks from a variety of places.

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