How do you disable the BACK button of browser to avoid incomplete payments on Paypal

How do you disable the BACK button. If they click SUBMIT and it takes them to Paypal to pay and then click the BACK button instead. The payment is NOT processed but the form is cleared and submitted (ordered) without a payment. PLEASE HELP!

When the user submits the form, gets redirected to the Paypal page, then abandoned the page, or pressed the back button of the browser, it will be considered as an INCOMPLETE PAYMENT SUBMISSION. It will only be posted as a valid submission if the user completed the payment and was able to completely process the transaction.

Here's a guide on how-to-view-incomplete-payments-of-your-payment-forms.

Now, we cannot circumvent this default browser feature, but I would suggest checking the IPN setting of your PayPal account and enable it.

The following guide should help you:  How-to-Enable-IPN-for-Paypal. In this way, you would be notified if someone tried to make a submission to your form but abandoned or didn't complete the payment transaction.