private void txt_Model_TextChanged(object sender, TextChangedEventArgs e)
 {
     connect = new CTUConnection();                  // refreshens the 'CTUConnection' class //
     connect.SelectOldVehicle();                     //*Selects the specified columns in the Patient table*//
     connect.SearchOldModel(txt_Model.Text);         //Searches the customer's 'name' within the populated table//
     DGV_Used_DemoCar.ItemsSource = connect.dataset; //*All the selected fields are filtered inside the table and stored inside the grid-view*//
 }