private void setMaximalPriceToolStripMenuItem_Click(object sender, EventArgs e) { if (listView1.SelectedIndices.Count == 0) { return; } FormNumberInput FNI = new FormNumberInput("Set new price", 0.0001, 100, OrderContainer.GetMaxPrice(listView1.SelectedIndices[0]), 4); if (FNI.ShowDialog() == System.Windows.Forms.DialogResult.OK) { OrderContainer.SetMaxPrice(listView1.SelectedIndices[0], FNI.Value); } }