private void button2_Click(object sender, EventArgs e)
        {
            SqlCommand gonder = new SqlCommand("INSERT into BANA_ONERI (ONERI) values (@P1)", bgl.baglan());

            gonder.Parameters.AddWithValue("@P1", richTextBox2.Text);
            gonder.ExecuteNonQuery();
            bgl.baglan().Close();
            liste();
            gor = new onerileri_gor();
            gor.Show();
        }
 private void button5_Click(object sender, EventArgs e)
 {
     on = new onerileri_gor();
     on.Show();
 }