//addButton_Click Action private void addButton_Click(object sender, EventArgs e) { //Check UNIQUE if (_customerManager.IsNameExists(customerNameTextBox.Text)) { MessageBox.Show(customerNameTextBox.Text + " Already Exists!"); return; } bool isAdded = _customerManager.AddCustomerInfo(customerNameTextBox.Text, customerAddressTextBox.Text, contactTextBox.Text); if (isAdded) { MessageBox.Show("Saved"); showDataGridView.DataSource = _customerManager.Display(); } else { MessageBox.Show("Not Saved"); } }