how i pristine before preference an asp:treeview an updatepanel?

i have an asp.net 2.0 page contains twin updatepanels. initial quarrel contains treeview. second quarrel contains tag triggered preference tree. i name node tag gets updated approaching treenode i clicked becomes highlighted formerly comparison node longer highlighted. however node uncanny highlighted(selected) code-behind rhythm private selecting another node.

the markup

<asp:updatepanel id="updatepanel1" runat="server" childrenastriggers="false" updatemode="conditional">
   <contenttemplate>
      <asp:treeview id="treeview1" runat="server" onselectednodechanged="treeview1_selectednodechanged">
         <selectednodestyle backcolor="pink" />
      </asp:treeview>
   </contenttemplate>
</asp:updatepanel>
<asp:updatepanel id="updatepanel2" runat="server" childrenastriggers="true">
   <contenttemplate>
      <asp:label id="label1" runat="server" text=" - "></asp:label>
   </contenttemplate>
   <triggers>
      <asp:asyncpostbacktrigger controlid="treeview1" eventname="selectednodechanged" />
   </triggers>
</asp:updatepanel>

the formula behind

protected vacant page_load(object sender, eventargs e)
{
   (!ispostback)
   {
      treeview1.nodes.add(new treenode("test 1", "test one"));
      treeview1.nodes.add(new treenode("test 2", "test two"));
      treeview1.nodes.add(new treenode("test 3", "test three"));
      treeview1.nodes.add(new treenode("test 4", "test four"));
      treeview1.nodes[0].selected = true;
   }
}

protected vacant treeview1_selectednodechanged(object sender, eventargs e)
{
   label1.text = treeview1.selectedvalue;
}

the during start initial node selected. since the rhythm private selecting another node?

also, i asked opposite i haven't got an answer for. any assistance appreciated.

edit i know sourroundings childrenastriggers="false" work nonetheless i wish prevaricate digest tree again unequivocally large.