sorry for the late , so i want to add the product price in the invoice line based on the selected pricelist i modified the name_search() function in product.py to return the product price but i want to get the price based on the pricelist :) here is a screenshot : farm9.staticflickr.com/8269/8703512253_59431df303_b.jpg

I cannot see the picture, but given your answer, you want to get the (original) price of the produc, based on the pricelist? To get this to work, you have to create a new module, extend sale.order.line (method on_change_product) and extend product.pricelist (create new method get_price_product; flow should be like product_pricelist.price_get_multi). I am working on a solution like this, and others have done that as well.