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;
using System.Web.Security;
using OnlineUsersProxy;

public partial class Login : System.Web.UI.Page
{
    
    protected void Page_Load(object sender, EventArgs e)
    {
        if ((txtUserID.Text.ToUpper() == "NARESH" ||
            txtUserID.Text.ToUpper() == "KESHAGON" ||
            txtUserID.Text.ToUpper() == "RAJESH")
            && txtPassword.Text == "Test@123")
        {
            OnlineUsersProxy.OnlineUsersServiceClient objOnlineUsers = new OnlineUsersProxy.OnlineUsersServiceClient();
            Member mem = new Member();
            mem.UserId = txtUserID.Text;
            switch(mem.UserId.ToUpper())
            {
                case "KESHAGON": mem.DisplayName = "Narsimlu Keshagouni"; break;
                case "NARESH": mem.DisplayName = "Naresh Reddy"; break;
                case "RAJESH": mem.DisplayName = "Rajesh Kumar"; break;
            }
            objOnlineUsers.AddOnlineUser(mem);            
            FormsAuthentication.RedirectFromLoginPage(txtUserID.Text, false);
        }
    }
}