How to add a extra feild in printout bill?

I want to add a MRP rate also in my bill???when i take a printout for sales invoice i want add a MRP rate also i a todo this ???


You should enter tax include item rate in the Price List Rate or Basic Rate field in the Sales Invoice.

In the tax table, check “is this Tax included in Basic Rate?”.

when i create bill …that bill has some feild like item,qty,price and total…but i want to include a MRP rate also After the Qty Feild in the bill…