Cross Domain/Platform Authentication and Data Transfer

<%@ Page Language="C#" MasterPageFile="~/Site1.Master" AutoEventWireup="true" CodeFile="LandingPage1.aspx.cs" Inherits="LandingPage1" Title="LandingPage1" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <br />
    <asp:GridView ID="gvUserData" runat="server" CellPadding="4" ForeColor="#333333" GridLines="None" Caption="Display authenticated user data">
        <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
        <RowStyle BackColor="#EFF3FB" />
        <EditRowStyle BackColor="#2461BF" />
        <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
        <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
        <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
        <AlternatingRowStyle BackColor="White" />
    </asp:GridView>
    <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Check Authentication Status" /><br />
    <br />
    <asp:Label ID="lblError" runat="server" CssClass="error-text" Width="100%"></asp:Label>
    
</asp:Content>