Problem in Treeview on Master Page

I have treeview conreol on master page.
when i click on parent it get expanded.
but problem is other parent node remains expanded.
i want solution that all other parent node except current clicked node should not get expanded.
they must be automatically shrink or collapse
Please help urgent!
<asp:TreeView ID="TreeView1" runat="server" ImageSet="Arrows" MaxDataBindDepth="0"
                                OnSelectedNodeChanged="TreeView1_SelectedNodeChanged" OnTreeNodeExpanded="TreeView1_TreeNodeExpanded"
                                Width="190px">
&nb ...