I am having a brain freeze. plz assist/advise. (The idea on this ongoing project keeps changing on me, but i think this is what we really wanted).
My new suitelet will be called from sales order, carries over customerid and customer name, has only two fields: Cutoff Date and Item Category (drop-down record/list).  Once the button is clicked on the suitelet, the calculation should be performed based on the above two criteria and the item sublist on the sales order or customer record.   i.e. Add up the amounts of sales since the cutoff date for one item category (by looping through the items purchased - both cash sales and sales order for one item category).