Keep fields saved when going thru checkout

[cLin]

As a customer checks out and stumbles upon an error on payment page, if he had the comment field with something written in it, the page essentially refreshes, shows the error message and wipes the comment field clean. Is their any to make it so the customer's input is saved before error checking or going back? If I'm on the confirmation page and I click back to the payment page, everything is wiped back to default. My CC info (I used the Paypal Direct module) and comments box are gone.