I'm trying to create a calculation for a product/payment field and not having much luck.

I've one Multiple Product field [Membership Level] which also is the controlling field for conditional results. This field has base values in it. These values are transferred to the Total field, no problem.
Now I also need to add an amount based on a quantity*.2 to be added to the base value. Essentially, an Educational Organization needs to pay $485 base plus .20 per student for membership.
I can't seem to get these values to combine in to update the Total field. Anyone have any suggestions? I'm either using the wrong kind of field or something.

Hello,

You can take a look at the following article for an example on this topic:
www.rsjoomla.com/support/documentation/r...o-a-paypal-form.html

Another option would be to use a script in "PHP Scripts" > "Scripts called on form process" in order to add the calculated total to the payment specific total field ( in this example the custom total is stored in a field named "total"):
$_POST = $_POST;

Thanks !