var loginRequest = new Login(Protocol, operationRequest);

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Photon.SocketServer;
using Photon.SocketServer.Rpc;
using ServerWF.Common;
using System.Net;
using System.Data;
using ExitGames.Logging;

namespace ServerWF.Operations
{
     public class Login:BaseOperation
     {
         private readonly ILogger Log = LogManager.GetCurrentClassLogger();

         public Login(IRpcProtocol protocol, OperationRequest request)
             : base(protocol, request)
         {
             string www = new WebClient().DownloadString("http://oneshoot.besaba.com/Login.php?user=" + UserName + "&password=" + Password);
             switch (www.ToLower())
             {
                 case "username does not exist!":
                     Log.Debug("Username does not exist!");
                     break;
                 case "login successfully!":
                     Log.Debug("Login successfully!");
                     break;
                 case "password does not match!":
                     Log.Debug("Password does not match!");
                     break;
             }
         }

         [DataMember(Code = (byte)ParameterCode.UserName)]
         public string UserName { get; set; }
         [DataMember(Code = (byte)ParameterCode.Password)]
         public string Password { get; set; }
     }
}

var loginRequest = new Login(Protocol, operationRequest);

username does not exist!