private void BtnAddColour_Click(object sender, EventArgs e) { if (IsValidate()) { string colourAndCode = $"{txtColourCode.Text.ToUpper()} - {txtColour.Text.ToUpper()}"; JobColoursModel newJobColour = new JobColoursModel() { Colour = colourAndCode }; List <JobColoursModel> colours = PrepAndPaintDB.GetJobColours(); foreach (var item in colours) { if (item.Colour == newJobColour.Colour) { MessageBox.Show($" Colour: {newJobColour.Colour} already exist", "Exist already!", MessageBoxButtons.OK, MessageBoxIcon.Error); txtColourCode.Focus(); return; } } colourName = PrepAndPaintDB.AddColour(newJobColour); DialogResult = DialogResult.OK; } }