treeview asp.net 2.0 issue

[vincenzo.papa]

I' ve got a TreeView asp.net 2.0 and I'm working in "ajax" way to allow
the nodes charge without the page postback. But I noticed that the
TreeNodePopulate is called back just the first time tha a node is
expanded. In fact,after the call at first expand, even the javascript
of
reference changes! (from TreeView_PopulateNode into
javascript:TreeView_ToggleNode)

Is it possible to call it back each time I expand a node? Or : is it
possible to generate TreeNodeExpanded method in ajax way?

Tnx,
Vincenzo Papa.