How do I tally values that only have a ticked Check Box next to them?

Question

Hi Folks,
I'm new to Acrobat forms and have recently finished a complicated 7 page form for a client and I am quite pleased with it.
But the client has come back with the following request:
They want Check Boxes next to a series of values and, when a Check Box is ticked, it only adds that ticked value. To show what I mean, please see the below image.
So basically, there is a field on the left-hand side (Current Monthly Repayments) that tallies all the values - in my example this totals $50.00. Then, there is a field on the right-hand side (Future Monthly Repayments) that needs to tally only the values that have a ticked "Yes" Check Box next to them. In my example, this would produce a tally of $20.00.
Does anyone know how this could be done?
Thank you

Answer 1

Yes, that's perfect. Try the following custom calculation script:
// Custom calculation script for future monthly repayments field
(function () {
     // Initialize variables
     var i, cb, v, sum = 0;
     // Loop through each row and add repayment value if Yes is checked
    for (i = 1; i < 7; i += 1) {
        // Get the value of the check box
        cb = getField("CashFlowCheck" + i).valueAsString;
        // Get the value of the repayment field, as a number
        v = +getField("CashFlow" + i).value;
        // Add the value to the sum if the check box is checked
        if (cb === "Yes") {
            sum += v;
    // Set this field's value to the sum, rounded to the nearest cent
    event.value = util.printf("%.2f", sum);