I have searched the world over and can't figure out how to do this

I have a suitelet that returns a saved search and have added a checkbox that will eventually check a field on each record that is checked when the submit button is checked.  That is no problem the issue I have is I want to get a running total of a field from the search, Amount, this will give me the amount for each line that is checked and if a line is unchecked will reduce the total by the amount unchecked. I know this has to happen on the client side but I cannot figure out how to get the