private void eqBtn_Click(object sender, EventArgs e) { double d; double newFeed; if (Double.TryParse(screen.Text, out d)) { Double.Parse(screen.Text); } try { newFeed = d; screen.Text = Calc.Equall(results, newFeed, operations); } catch (Exception ex) { MessageBox.Show(ex.Message); } double doe; if (Double.TryParse(screen.Text, out doe)) { results = Double.Parse(screen.Text); } operations = ""; show.Text = ""; }