[xwiki-users] navigator tree

Hi xWiki users, I am quite new in using xWiki and I am very satisfied with it, but I can't solve one problem. I want to create some navigator which will have a tree structure. I found a SpaceExplorer Aplication and a source code of a tree, it works fine when I paste the code into a page, but when I paste it to a panel (because I would like to use the tree for navigation), it works but not very well. The tree isn't perfectly structured and what is worse, there is some error on the server. In Firefox there is a message: Server failed:internal error, IE: there is a message: Error on the line 81, but in a log I didn't find anything wrong. When I remove this panel everything is OK. In documentation I have read that panels use wiki syntax 1.0 maybe this is the reason why it doesn't work fine. But I don't know how to solve it. I will be very glad for any point. Thanks a lot Zuzana