I don't clearly understand what is in your checkboxes and what you want to do.
Please provide a more clear description and an answer should come soon.
I am trying to make an invoice script that sends invoice data to the database. There is a Quantity text box, Item Description text box, Unit price text box, Subtotal text box and Tax checkbox. The Tax checkbox is present since not all things have to be taxed, but if they do the Tax checkbox needs to be checked so that the subtotal can be multiplied by the certain tax percentage. I need to be able to detect all of the checkboxs that are checked multiply them by their subtotals and then add all of these values together in the Tax Total text box.
well to be honest, a proper solution can only be made if we are able to see what you already wrote and how you setup your checkboxes.
but.. here's a hint:
put a change event on every checkbox that calls up the calculate method, in the calculate method you switch/case the name of the checkbox and calculate based on the result of the selected checkbox, does this make sense?
Otherwise you can post your code here, and I will see what i can do