private void btnAddMenu_Click(object sender, EventArgs e) { string validInputRegex = @"^\£?([0-9]{1,3},([0-9]{3},)*[0-9]{3}|[0-9]+)(.[0-9][0-9])?$"; Match match = Regex.Match(txtNMenuPrice.Text, validInputRegex, RegexOptions.IgnoreCase); if (!match.Success) { MessageBox.Show("Incorrect price format!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } if (Meat != null & Veg1 != null && Veg2 != null && Drink != null) { if (FoodMenu.Add(Meat, Veg1, Veg2, Drink, Convert.ToDecimal(txtNMenuPrice.Text))) { MessageBox.Show("Menu Added!", "SUCCESS", MessageBoxButtons.OK); LoadFoodMenus(); } else { MessageBox.Show("Failed to add Menu!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); } } else { MessageBox.Show("Please select one of each item!", "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } }