have a base.aspx with a frameset




I have a masterpageL.master that has a content place holder for treeview

Treeview

The TView.aspx corresponds to the above masterpageL.master and defines the TreeView





….




TView.aspx.cs Code behind file defines the event handler:
protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{
Session["tvNode"] = TreeView1.SelectedNode.Text;
}
The TreeView displays properly. When I select a treeview node it never hits the above TreeView1_SelectedNodeChanged event handler .

Also, when I select the treeview node, even the page_load does not get called.

Can someone help?