Modified A Hosted Payment Vendor - it worked then I broke it.

I took an existing payment vendor (CyberSource) for a hosted solution and modified it for my payment vendor (Official Payments).  It was working well and I was able to navigate to the vendor site with info, etc.  Then I modified the CheckoutOnepage.aspx code by changing some verbage on the checkout buttons (and opended the RemotePost into a new window), but now the confirm button won't redirect to my payment URL.  All I get is a blank browser page.
Could you explain a bit more the steps needed for supporting a hosted payment solution.  
Thanks!