Prevent credit card number from clearing when selecting different shipper

[corrado444]

When a customer lands on the check out page and they enter their credit card number BUT then they change their shipping method, the page refreshes and the credit card number field is cleared (not the name and the exp date though).

We used to have this problem a lot because our version of Zen cart did not pre-select a shipping method and a lot of customers filled out the CC fields only to get an error when continuing and they had to enter their CC# again. A bit annoying.

I have made a small change to the php code and now the Payment method is pre-selected and I think it will curtail future errors like this, but I noticed that any error on the checkout page and some operations such as choosing a different shipping method refresh the page and delete the CC# and the CSV number.

I think this is actually by design, but I was wondering if there was a way to have the CC# and CSV to remain persistent even if the checkout page was reloaded or if that is a built in behavior that can't be changed.

I hope I explained my problem properly.

Edit: I have actually found anotehr post where the poster is actually looking for the opposite behavior. His problem was that the CC field "remembered" the CC# even after the page was refreshed. We would like it to "remember" the CC number after a page refresh but it "forgets" it.

here is the link to that post: http://www.zen-cart.com/forum/showthread.php?t=65568

Thank you