public override void AddNew(IWin32Window owner)
        {
            Category category = CategoryEditor.CreateCategory(owner);

            if (category != null)
            {
                this.categories.Add(category);
            }
        }
        private void cboCategories_AddNewValue(object sender, AddNewValueEventArgs e)
        {
            var category = CategoryEditor.CreateCategory(this);

            if (category != null)
            {
                categories.Add(category);
                e.Cancel   = false;
                e.NewValue = category.ID;
            }
            else
            {
                e.Cancel = true;
            }
        }