VAT and Shipping charges

VAT and Shipping charges

Hi,

I have two question.


Question #1:
We can configure VAT in two places, one is at item level and one is at Salesorder order at item level. I want that VAT at salesorder is not changed and is readonly. Is it possible?

Question #2
I have created shipping charges custom field on item module and if i add item in salesorder, the shipping charges at salesorder is sum of shipping charges of individual item. Is it possible?