private void buttonInsertPerfomance_Click(object sender, EventArgs e) { if (textBoxAuthorId.Text == "" || textBoxCircumstancesPerformance.Text == "" || textBoxSongName.Text == "") { MessageBox.Show("Wrong input!"); return; } ISongsRepository songsRep = new SongsRepository(); bool flag = songsRep.AddPSong(textBoxSongName.Text, textBoxCircumstancesPerformance.Text, Convert.ToInt32(textBoxAuthorId.Text)); if (flag) { MessageBox.Show("Posted!"); } else { MessageBox.Show("Error!"); } textBoxAuthorId.Text = ""; textBoxCircumstancesPerformance.Text = ""; textBoxSongName.Text = ""; }