private void can_Submit_MouseDown(object sender, MouseButtonEventArgs e) { connect = new CTUConnection(); if (txt_serial.MaxLength != 13 || string.IsNullOrEmpty(txt_serial.Text)) { MessageBox.Show("Please enter a serial number for the vehicle"); } else if (string.IsNullOrEmpty(txt_Brand.Text)) { MessageBox.Show("Please enter the serial number of the vehicle"); } else if (string.IsNullOrEmpty(txt_Color.Text)) { MessageBox.Show("Please enter the color of vehicle"); } else if (string.IsNullOrEmpty(txt_Model.Text)) { MessageBox.Show("Please enter the model of the vehicle"); } else if (string.IsNullOrEmpty(txt_Price.Text)) { MessageBox.Show("Please enter a serial number for the vehicle"); } else { connect.GetNewVehicles(txt_Brand.Text, txt_Model.Text, txt_serial.Text, txt_Color.Text, txt_Price.Text, Convert.ToDateTime(DTP_Year.SelectedDate.ToString())); } }