private void modifySupplierBtn_Click(object sender, EventArgs e)
        {
            AddProductSupplierFrm modProdSup = new AddProductSupplierFrm();

            modProdSup.currentProductSupplier = currentProductSupplier;
            modProdSup.AddButton = false;
            modProdSup.ShowDialog();
            Display();
        }
        private void addSupplierBtn_Click(object sender, EventArgs e)
        {
            AddButton = true;
            AddProductSupplierFrm addProdSup = new AddProductSupplierFrm();

            addProdSup.AddButton = AddButton;
            addProdSup.ShowDialog();
            Display();
        }