private void SalesManagerForm_Load(object sender, EventArgs e) { textBoxCustomerID.Enabled = false; // Disable CustomerID textBox comboBoxSearch.Items.Add("CustomerID"); comboBoxSearch.Items.Add("CustomerName"); comboBoxSearch.Items.Add("City"); comboBoxSearch.Items.Add("PostalCode"); comboBoxSearch.Items.Add("PhoneNumber"); comboBoxSearch.Items.Add("FaxNumber"); comboBoxSearch.Text = comboBoxSearch.Items[0] as string; SalesManager salesManager = new SalesManager(); this.dsProject = salesManager.CreateDataSetTable(this.dsProject, this.dtCustomer); salesManager.ReadData(this.dsProject, this.dtCustomer); dataGridViewDisplay.DataSource = dtCustomer; }