private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { comb.Combo1(album_comb.Text, author_comb.Text, gener_comb.Text, singer_comb.Text, money.Text, db); song_comb.Items.Clear(); foreach (Song song in db.AllC()) { this.song_comb.Items.Add(song.name + "_" + song.author); } }