I'm using a CSS dropdown menu addon (this one to be exact http://www.zen-cart.com/index.php?ma...roducts_id=479) and I've come across a small problem.

Since I have a lot of categories on the site, whenever the "Categories" dropdown menu appears, it temporarily extends the page until it loses focus.

What I'm trying to do is edit the code (which I haven't touched) to make it so that once 10 categories are listed, add a "More" option at the end that links to the sitemap. How can I do this?