various fileds in reports

i am preparing a Proforma invoice report in which i want have to various fields as follows:

Bank Commission

Bank Forwading Charges

Bank Interest

Handling Charges

Sales Discount

Prepayment Amt
from which data item i should take these filelds.

For Porforma Invoice you should look at the sales header and sales line table only

But you need to add some of the above fields for capturing data in table.