public static CheckResult ValidateSave(DSModel db, UserModel user)
        {
            CheckResult res = new CheckResult();
            if (string.IsNullOrWhiteSpace(user.Username))
                res.AddError("Please enter a Username!", user.GetName(p => p.Username));
            if (string.IsNullOrWhiteSpace(user.FirstName))
                res.AddError("Please enter a First Name!", user.GetName(p => p.FirstName));
            if (string.IsNullOrWhiteSpace(user.LastName))
                res.AddError("Please enter a Last Name!", user.GetName(p => p.LastName));

            var check = db.Users.Where(u => u.Username == user.Username && u.UserID != user.UserID).FirstOrDefault();
            if (check != null)
                res.AddError("Another user already uses this username!", user.GetName(p => p.Username));

            return res;
        }
        private void BindModel(UserModel user)
        {
            BindingSource bsUser = new BindingSource();
            bsUser.DataSource = user;

            Username.DataBindings.Add("EditValue", bsUser, user.GetName(p => p.Username), true, DataSourceUpdateMode.OnPropertyChanged);
            Password.DataBindings.Add("EditValue", bsUser, user.GetName(p => p.Password), true, DataSourceUpdateMode.OnPropertyChanged);

            FirstName.DataBindings.Add("EditValue", bsUser, user.GetName(p => p.FirstName), true, DataSourceUpdateMode.OnPropertyChanged);
            SecondName.DataBindings.Add("EditValue", bsUser, user.GetName(p => p.SecondName), true, DataSourceUpdateMode.OnPropertyChanged);
            LastName.DataBindings.Add("EditValue", bsUser, user.GetName(p => p.LastName), true, DataSourceUpdateMode.OnPropertyChanged);

            IsEnabled.DataBindings.Add("Checked", bsUser, user.GetName(p => p.IsEnabled), true, DataSourceUpdateMode.OnPropertyChanged);
            IsAdmin.DataBindings.Add("Checked", bsUser, user.GetName(p => p.IsAdmin), true, DataSourceUpdateMode.OnPropertyChanged);
        }