Silviaa,

To reload all of you order lines, you need to write your customize functionality,

i also faced this scenario, so i have created one for me,

Whenever you select a client  from client widget, and click on 'Change Customer' you have to call this customized method(under click event of '.next' button of ClientListScreenWidget).

this.$('.next').click(function(){ var order = self.pos.get_order();

   self.save_changes();

   self.refresh_orderlines(order); //CUSTOMIZED METHOD

   self.gui.back(); // FIXME HUH ?

  });

And here is the method:

refresh_orderlines: function(order){

    var lines = jQuery.extend(true, {}, order['orderlines']['models']);    

     //looping through each line  

    $.each(lines, function(k, line){

         var my_prod = line['product'];

         order.select_orderline(line); 

         //simulating product click event and create new duplicate order line

         if ($(".product[data-product-id='"+my_prod['id']+"']").length == 0){             order.pos.gui.screen_instances.products.click_product(my_prod);

         }

         else{

             $(".product[data-product-id='"+my_prod['id']+"']").trigger('click');

         }

         //removing original order line

         line.set_quantity('remove');

  });

  //saving new created lines

  order.trigger('change');

 },

Hope it helps!