Ok, we're trying to replicate the functionaility we used to have with the old web tree. We build our tree in codebehind as our entity based datasource is complex and it gives us greater control in terms of highlighting nodes and restoring the tree state. We used to take advantage of the tag property of node. This allowed us to attach any serialisable object  to a node and get the value from the client, in practise and for performance this was normally restricted to an int normally representing the id of the dataitem in question. How can we accomplish this with the new tree?