private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            str = dataGridView1.CurrentCell.Value.ToString();
            string Path = "C:\\Users\\ahmed\\Desktop\\PDF\\" + str + ".pdf";


            if (Path != null)
            {
                Pdfreader.src = Path;
                Pdfreader.Show();
                textBox1.Hide();
                button1.Show();
                dataGridView1.Hide();
            }
        }
 public void disable()
 {
     Pdfreader.Hide();
     button1.Hide();
 }