private void salesFormToolStripMenuItem_Click(object sender, EventArgs e)
        {
            transactionType = "Sales";
            PurchaseAndSales sales = new PurchaseAndSales();

            sales.Show();
        }
        private void userToolStripMenuItem_Click(object sender, EventArgs e)
        {
            transactionType = "Purchase";
            PurchaseAndSales purchase = new PurchaseAndSales();

            purchase.Show();
        }