private void button_AddToCart_Click(object sender, EventArgs e)
        {
            try
            {
                var cardIndex = dataGridView_CardData.CurrentCell.RowIndex;
                var cartIndex = dataGridView_Carts.CurrentCell.RowIndex;

                var cardExpansion = dataGridView_CardData.Rows[cardIndex].Cells["Year"].Value.ToString();
                var cardCategory  = dataGridView_CardData.Rows[cardIndex].Cells["Brand"].Value.ToString();
                var cardNumber    = dataGridView_CardData.Rows[cardIndex].Cells["Number"].Value.ToString();
                var cardName      = dataGridView_CardData.Rows[cardIndex].Cells["Category"].Value.ToString();

                var cartID = Convert.ToInt32(dataGridView_Carts.Rows[cartIndex].Cells["CartID"].Value);

                var name = cardName + " - " + cardNumber;
                var set  = cardExpansion + ": " + cardCategory;

                var cardID = dataGridView_CardData.Rows[cardIndex].Cells["CardID"].Value.ToString();

                CartManager.AddItemToCart(cartID, cardID, name, set, 1);
            }
            catch (Exception ex)
            {
                //TODO: Message? Issue is most likely having not selected a cart or card
            }
        }