AJAX tree menu - working code sample

I need a clean and simple code sample of a page that has two panels. The left panel will have a tree and when a user opens folders of the tree and gets to a node, the link associated with the node will retrieve an internal page and place it in the right panel. The tree should: 1. keep the state of the menu is saved in cookie 2. the links should visible to search engines. It would also be great if the selected tree node was highlighted. Here is an example of such tree (it can be used in the code sample): [login to view URL]