1. server side in the sql query statement when you query for data or in the php code after the query.
2. and/or on the client side in javascript after user input.

jqGrid, however, does allow you to define events that trigger functions to allow you to do calculations at various points and fields. Either way, you will have to do the coding to calculate subtotals, taxes, surcharges, totals and so on…

good luck.

My specific question with a specific reference:

Referring to the tutorial for a basic example, you have a :

Date,Client,Amount,Tax,Total that correspond to an invoice number.

The dollar amounts for amount is $1000, tax is 0; so total is $1000.

I would like if I enter 500 into tax, that it calculates the total and displays it as 1500.  I know that in this basic page total is not part of a calculation, but I'd like to learn how to incorporate that into my project.

Please advise if this is possible and point me in the right direction.

Thanks a lot,

Ben