private void bfbtn_EditBooks_Click(object sender, EventArgs e)
        {
            EditBooks eb = new EditBooks();

            eb.Show();
            this.Hide();
        }
        private void bfbtn_Delete_Click(object sender, EventArgs e)
        {
            EditBooks eb = new EditBooks();

            eb.Owner = this;
            eb.Show();
            istek = true;
        }