Web Forms :: Visible And Invisible Treeviewmenus In Masterpages?

This is my treeview code. when i enter through orderentryhome page i want to invisible savedordermenu and checkout menu. If i click submit button in organizationdetails.aspx page then savedordermenu and checkoutmenu will diaplay along with other menus. This is my requirement.

<asp:TreeView ID="trvMaster" runat="server" ForeColor="#E9CF24" Width="157px"
ExpandDepth="2" ShowLines="True">
<Nodes>
<asp:TreeNode Text="File Maintanence" Value="File Maintanence">
<asp:TreeNode Text="Organization" NavigateUrl="~/FileMaintenance/frm_vieworganization.aspx"
Value="Organization"></asp:TreeNode>
<asp:TreeNode Text="Vendor" NavigateUrl="~/FileMaintenance/frm_ViewVendors.aspx"
Value="Vendor"></asp:TreeNode>
<asp:TreeNode Text="Items" NavigateUrl="~/FileMaintenance/frm_Items.aspx" Value="Items">
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Order Entry" Value="Order Entry">
<asp:TreeNode Text="Organization List" NavigateUrl="~/OrderEntry/frm_OrganizationDetails.aspx"
Value="Organization List"></asp:TreeNode>
<asp:TreeNode Text="Saved orders" NavigateUrl="~/OrderEntry/frm_savedorder.aspx"
Value="Saved Orders"></asp:TreeNode>
<asp:TreeNode Text="Order Entry" NavigateUrl="~/OrderEntry/frm_OrderEntry.aspx" Value="Order Entry">
</asp:TreeNode>
<asp:TreeNode NavigateUrl="~/OrderEntry/frm_Deliveries.aspx" Text="Deliveries" Value="Deliveries">
</asp:TreeNode>
<asp:TreeNode NavigateUrl="~/OrderEntry/frm_Shortout.aspx" Text="ShortOut" Value="ShortOut">
</asp:TreeNode>
<%-- <asp:TreeNode NavigateUrl="~/OrderEntry/OrderEntryHome.aspx"
Text="Order Entry Home" Value="Order Entry Home"></asp:TreeNode>--%>
<asp:TreeNode NavigateUrl="~/OrderEntry/CheckOut.aspx" Text="Checkout" Value="Checkout">
</asp:TreeNode>
</asp:TreeNode>
<asp:TreeNode Text="Draft Bids" Value="Draft Bids"></asp:TreeNode>
</Nodes>
</asp:TreeView>