private void btnPurchase_Click(object sender, EventArgs e)
        {
            purchaseForm.GetStudyRoomNumber(_str);

            List <Item> items = Dao.Item.GetAll();

            foreach (var price in items)
            {
                if (txbPrice.Text == price.Price.ToString() && txbItemName.Text == price.Name.ToString())
                {
                    purchaseForm.AddItem(price);
                }
            }
            DialogResult = DialogResult.Yes;
            Close();
        }