private void login_process()
        {
            if (txtPass.Text == null || txtPass.Text == "")
            {
                MessageBox.Show("패스워드를 입력하세요.");
                return;
            }

            HashAlgorithm hash = new SHA256Managed();

            byte[] plainTextBytes = System.Text.Encoding.UTF8.GetBytes(txtPass.Text);
            byte[] hashBytes      = hash.ComputeHash(plainTextBytes);

            //in this string you got the encrypted password
            string hashValue = Convert.ToBase64String(hashBytes);

            //로그인시 서버에 접속할 수 없으므로 WCF를 이용하여 처리
            ChannelFactory <WcfIService> factory = new ChannelFactory <WcfIService>();
            // Address
            string address = "net.tcp://52.141.56.159:5443/WcfService";

            //string address = "net.tcp://localhost:5443/WcfService";
            factory.Endpoint.Address = new EndpointAddress(address);

            NetTcpBinding netTcpBinding = new NetTcpBinding();

            netTcpBinding.Security.Mode = SecurityMode.None;

            // Binding : TCP 사용
            factory.Endpoint.Binding = netTcpBinding;
            // Contract 설정
            factory.Endpoint.Contract.ContractType = typeof(WcfIService);
            // Channel Factory 만들기
            WcfIService channel = factory.CreateChannel();
            // Server 쪽 함수 호출
            Hashtable _userInfo = channel.LoginCheck(txtUserId.Text.Trim(), hashValue);

            // Close Channel
            ((ICommunicationObject)channel).Close();

            String[] login_user_info = new string[12];

            if (_userInfo != null)
            {
                //var user = _list[0];
                login_user_info[0] = txtUserId.Text.Trim();
                login_user_info[1] = _cu.rtnHtS(_userInfo["SWCD"]);
                login_user_info[2] = _cu.rtnHtS(_userInfo["NAME"]);
                login_user_info[3] = _cu.rtnHtS(_userInfo["LEVEL_CD"]);
                login_user_info[4] = _cu.rtnHtS(_userInfo["ADMIN"]);
                login_user_info[5] = _cu.rtnHtS(_userInfo["ORG_CD"]);
                login_user_info[6] = _cu.rtnHtS(_userInfo["GROUP_ID"]);
                login_user_info[7] = _cu.rtnHtS(_userInfo["BADMIN"]);
                login_user_info[8] = txtPass.Text;

                login_user_info[9]  = serverIP.Text;
                login_user_info[10] = serverPort.Text;

                login_user_info[11] = txtPass.Text;

                MainProg.ConfigWriteProfile(login_user_info[0], login_user_info[9], login_user_info[10]);

                MainProg.CConf.userId = login_user_info[0];

                this.Visible = false;
                MainForm mf = new MainForm(login_user_info);
                mf.Show();
            }
            else
            {
                MessageBox.Show("패스워드를 다시 입력하세요.");
                return;
            }
        }