[jQuery] [TreeView] - How to collapse a menu item that is a link?

[eclipseTalk]

Hi,
I'm looking at the "JQuery TreeView - Sample 0" from
http://jquery.bassistance.de/treeview/demo/?1
Great work!
I have a question. How can I make the menu collapse upon clicking?
When I click, the menu expands, but if I click again the menu doesn't
collapse. Any help is appreciated.
Thanks in advance....