private async void InsertItemButton_Click(object sender, EventArgs e)
        {
            if (CheckNulls(InsertItem))
            {
                DisableControls(InsertItem);
                Item item = new Item()
                {
                    Name        = ItemName.Text,
                    Description = ItemDescription.Text,
                    Main        = mainCategories[ItemMainCategory.SelectedIndex],
                    Sub         = subCategories[ItemSubCategory.SelectedIndex]
                };
                await Task.Run(() =>
                {
                    cms.InsertItems(item);
                    cms.TerminateConnection();
                });

                EnableControls(InsertItem);
                Close();
            }
        }