private void buttonAdd_Click(object sender, EventArgs e)
        {
            if (textBoxTitle.Text == "" || textBoxDirector.Text == "" ||
                comboBoxCategory.SelectedIndex == -1 || comboBoxGenre.SelectedIndex == -1)
            {
                MessageBox.Show("Complete data");
            }
            else
            {
                string description = "";

                if (textBoxDescription.Text != null)
                {
                    description = textBoxDescription.Text;
                }

                moviesService.AddMovie(textBoxTitle.Text, textBoxDirector.Text, dateTimePickerRelease.Value.ToString("yyyy-MM-dd"),
                                       Int32.Parse(comboBoxGenre.SelectedValue.ToString()),
                                       Int32.Parse(comboBoxCategory.SelectedItem.ToString()),
                                       Int32.Parse(numericUpDownDuration.Value.ToString()),
                                       description);

                MessageBox.Show("Movie added to database");
                ClearInput();
                moviesService.GetMovies(dataGridViewMovies);
            }
        }