private void btnAdd_Click(object sender, EventArgs e)
        {
            Form_BookDetail f = new Form_BookDetail(0);

            f.d += new Form_BookDetail.MyDel(Show);
            f.Show();
        }
 private void btnEdit_Click(object sender, EventArgs e)
 {
     if (dataGridView1.SelectedRows.Count > 0)
     {
         int             masach = Convert.ToInt32(dataGridView1.SelectedRows[0].Cells["MaSach"].Value.ToString());
         Form_BookDetail f      = new Form_BookDetail(masach);
         f.d += new Form_BookDetail.MyDel(Show);
         f.Show();
     }
     else
     {
         MessageBox.Show("Select the row you want to update");
     }
 }