private void button3_Click(object sender, EventArgs e)
        {
            string t1;
            t1 = textBox1.Text;
            string delete = "delete from kitaplar WHERE ID='" + t1 + "'";
            MySqlCommand komut = new MySqlCommand(delete, baglanti);
            MySqlDataReader reader;
            baglanti.Open();
            reader = komut.ExecuteReader();
            MessageBox.Show("Veri Silindi");
            baglanti.Close();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            string komut = "SELECT * FROM stokbilgisi";
            MySqlDataAdapter da = new MySqlDataAdapter(komut, baglanti);
            DataTable dt = new DataTable();
            da.Fill(dt);
            dataGridView1.DataSource = dt;
        }