private void ArtNew_Click(object sender, EventArgs e)
        {
            var editForm = new EditArticleForm();

            editForm.ShowDialog();
            if (editForm.DialogResult == DialogResult.OK)
            {
                guide.Articles.Add(new WaterObject(editForm.Water));
                ArticleBindingSource.ResetBindings(false);
                guide.changed = true;
            }
        }
        private void ArtEdit_Click(object sender, EventArgs e)
        {
            if (!(ArticleList.SelectedItem is WaterObject item))
            {
                return;
            }
            int index    = guide.Articles.IndexOf(item);
            var editForm = new EditArticleForm(item);

            editForm.ShowDialog();
            if (editForm.DialogResult == DialogResult.OK)
            {
                guide.Articles[index] = new WaterObject(editForm.Water);
                ArticleBindingSource.ResetBindings(false);
                guide.changed = true;
            }
        }