When you use the table2 attribute intead of table in htmlb:tree, you can use 3 more attributes for each node ["clientClick", "textDirection" and "selection" (don't know what selection does, nothing?)].
With "clientClick", you can specify a javascript event-handler. I noticed that clientClick only works if you don't set the "link" attribute?
How can I use the "clientClick" and let the node look like a link (underlined etc) as well?