private void button1_Click(object sender, EventArgs e) { if (ModeltextBox.Text == null) ModeltextBox.Text = ""; if (MobsChoiceOpen != null) { MobsChoiceOpen.StartPosition = FormStartPosition.CenterScreen; MobsChoiceOpen.TopMost = true; MobsChoiceOpen.Show(); } else { MobsModelChoice fm = new MobsModelChoice(this, ModeltextBox); MobsChoiceOpen = fm; fm.TopMost = true; fm.Show(); } }