Adding columns to the estimates

Adding columns to the estimates

Hi,

In our estimates apart from the "Qty" and "Rate" columns sometimes we need the duration column also for example 3 months / 4 months etc.

How do we customize the estimate and invoices in order to add the duration column and multiply the three columns for the amount..

Thanks,

Rajesh K Kishanpuriya
Ideazfirst Marketing Services (P) Ltd
Kolkata, India