Show/hide sitemap if user is logged in

Question

I have a log in page, code behind is below:

protected void btnLog_Click(object sender, EventArgs e)

{

    SqlConnection conn1 = new SqlConnection("Data Source=GATE-PC\\SQLEXPRESS;Initial Catalog=dbUsers;Integrated Security=True");

    conn1.Open();

    SqlCommand cmdd = new SqlCommand("select * from Users where UserName = @user AND Password = @pass", conn1);

    SqlParameter param = new SqlParameter();

    SqlParameter param1 = new SqlParameter();

    param.ParameterName = "@user";

    param1.ParameterName = "@pass";

    param.Value = txtuser.Text;

    param1.Value = txtpass.Text;

    cmdd.Parameters.Add(param);

    cmdd.Parameters.Add(param1);

    SqlDataReader reader = cmdd.ExecuteReader();

    if (reader.HasRows)

    {

        reader.Read();

        MessageBox("Login Successful");

        clear();

    }

    else

    {

        MessageBox("Invalid Username/Password");

    }

}

I have two sitemaps:

<asp:Menu ID="NavigationMenu" runat="server" CssClass="menu" 

                EnableViewState="False" IncludeStyleBlock="False" Orientation="Horizontal" 

                DataSourceID="SiteMapDataSource1" StaticDisplayLevels="2" 

                onmenuitemdatabound="NavigationMenu_MenuItemDataBound">        

            </asp:Menu>      

            <asp:SiteMapDataSource ID="SiteMapDataSource1" runat="server" />

            <div class="clear hideSkiplink">              

            <asp:Menu ID="Menu1" runat="server" CssClass="menu" 

                EnableViewState="False" IncludeStyleBlock="False" Orientation="Horizontal" 

                DataSourceID="SiteMapDataSource2" StaticDisplayLevels="2" 

                onmenuitemdatabound="NavigationMenu_MenuItemDataBound">        

            </asp:Menu>      

            <asp:SiteMapDataSource ID="SiteMapDataSource2" runat="server" SiteMapProvider="AdminSiteMapProvider"/>

what i want to achieve is when a user is not logged in Menu1 will display and NavigationMenu will hide but if a user is logged in Menu1 will hide then NavigationMenu will show. Kindly help me with this. I'm using asp.net with c#. Thanks and God Bless