I can not see how these custom values can be carried over from the base form to the iFrame

I am using the custom value for the PayPal form since I have some calculations and conditional logic involved in creating my final price. I can not see how these values can be carried over from the base form to the iFrame.

Hi,

Unfortunately due to the forms being separate forms entirely, passing the value from one form to another form embedded within it, is not possible.  The custom calculation values may only be passed from the form that contains it. to another field within the same form.  The multiple payments only work if the full order process is contained to the payment field.

Please let us know if you have any further questions and we will be happy to help.

Thank you for using JotForm!

OK, thanks.

I've solved the issue by creating a 2nd for the paypal option, and populating using the URL method.

Glad to hear it!  Let us know if you have any further questions and we will be happy to help.