Change contents of page based on user login status in ASP.Net Membership

You need to use LoginView control

<asp:LoginView ID="LoginView1" runat="server">
    <AnonymousTemplate>
    <!--Content to be shown for non-logged in user -->
    </AnonymousTemplate>
    <LoggedInTemplate>
    <!--Content to be shown for logged in user -->
    </LoggedInTemplate>
    </asp:LoginView>

You need to configure your database to work with ASP.Net Membership controls refer

Configure existing database and website to work wi...