private void Form1_Load(object sender, EventArgs e)
{
dataGridViewDauSach.DataSource = dauSach.XemTatCaDauSach();
dataGridViewTacGia.DataSource = tacGia.XemTacGia(dataGridViewDauSach.CurrentRow.Cells[0].Value.ToString());
dataGridViewTheLoai.DataSource = theLoai.XemTheLoai(dataGridViewDauSach.CurrentRow.Cells[0].Value.ToString());
dataGridViewNhaXuatBan.DataSource = nhaXuatBan.XemNhaXuatBan(dataGridViewDauSach.CurrentRow.Cells[0].Value.ToString());
textBoxKeSach.Text = dataGridViewDauSach.CurrentRow.Cells[2].Value.ToString();
comboBoxLoaiThongTin.SelectedIndex = 0;
}