JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
How do your integrate paypal payment to the suggested donation amount and "other" amountAsked by gncjlim on May 05, 2015 at 06:51 PM
Please show us on how to do the calculate amount with suggested donation and "other" amount to be input by our customer
You can refer to this guide to see how to do this: https://www.jotform.com/help/275-How-to-pass-a-calculation-to-a-payment-field. You would need to add a calculation widget in your form and use it to pass its value to the payment gateway.
I've created this cloned version of your form: http://form.jotformpro.com/form/51247728598974 so you can see how it works. Feel free to clone the form to your account if you want to inspect it further.