private void showDataGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            AddSupplier addSupplier = new AddSupplier(this);

            if (showDataGridView.Columns[e.ColumnIndex].Name == "Edit")
            {
                addSupplier.supplierId                = Convert.ToInt32(showDataGridView.Rows[e.RowIndex].Cells[1].Value);
                addSupplier.codeTextBox.Text          = showDataGridView.Rows[e.RowIndex].Cells[2].Value.ToString();
                addSupplier.nameTextBox.Text          = showDataGridView.Rows[e.RowIndex].Cells[3].Value.ToString();
                addSupplier.addressTextBox.Text       = showDataGridView.Rows[e.RowIndex].Cells[4].Value.ToString();
                addSupplier.emailTextBox.Text         = showDataGridView.Rows[e.RowIndex].Cells[5].Value.ToString();
                addSupplier.contactTextBox.Text       = showDataGridView.Rows[e.RowIndex].Cells[6].Value.ToString();
                addSupplier.contactPersonTextBox.Text = showDataGridView.Rows[e.RowIndex].Cells[7].Value.ToString();
                addSupplier.saveOrUpdateButton.Text   = "Update";

                addSupplier.Show();
            }
        }
        private void addSupplierButton_Click(object sender, EventArgs e)
        {
            AddSupplier addSupplier = new AddSupplier(this);

            addSupplier.Show();
        }