[Zope] Tree navigation

hi everyone, this morning a list member had a question about how to synchronize a tree with a page being opened, i am trying to do the very same. it is not a problem to create a link to the specific document within the tree, but how can i make sure the tree that displays the navigational choices (it's in the standard_html_header of the document i am displaying) is in synch with the page i am linking to, meaning the book is "open"? something else. in regards to michel's Question, i think it might be really hard to adequately describe zope in one sentence.......................... :) Jens Vagelpohl