if( Auth::attempt(['mssv' => $username,'password' =>$password])) {
                $user=SinhVien::where('mssv',$username)->first();

       //i want to share $user to all view in here

                $success = new MessageBag(['successlogin' => 'Login Success]);
                return redirect()->back()->withErrors($success);
            }
else {
            $errors = new MessageBag(['errorlogin' => 'Login Fail']);
            return redirect()->back()->withErrors($errors);
        }

{{$user->name}}