ASP.NET Chatting using WCF Services and JSon

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        lblUser.Text = HttpContext.Current.User.Identity.Name;
        hidCurrentUser.Value = HttpContext.Current.User.Identity.Name;

        OnlineUsersProxy.OnlineUsersServiceClient wsOnlineUsers = new OnlineUsersProxy.OnlineUsersServiceClient("OnlineUserService");
        rptrOnlineUsers.DataSource = wsOnlineUsers.GetOnlineUsers(HttpContext.Current.User.Identity.Name);
        rptrOnlineUsers.DataBind();
    }
}