Checkout Success white screen problem

[Dutchman]

I'm using osCommerce 2.2-MS2 with Echo payment Module on Apache server running PHP Version 4.3.10.

When a transaction is completed using a credit card the checkout_sucess.php screen does not display, only a white screen with the checkout_process.php path in the header and nothing showing in view source but an empty header and body.
The transaction is successful, the card is charged and the order appears in my store. I just need the customer to see a checkout success screen.

If I make a purchase that fails verification the Echo_cc.php "'Verification of your account FAILED" screen displays OK.

[michael_s]

blank screen = php error. Check your error logs.

[Dutchman]

There are error logs? Where?

[michael_s]

Your server generates error logs. Your hosting company should provide access to them since you are running scripts. Check in your control panel. How else would you debug errors?

[Dutchman]

Thanks for the replies, I appreciate the help. And I found my log files, cool. I also found my problem.
I missed an insertion when I installed the Echo payment module. The broken variable was causing the php error which equalled a white screen.
I knew it was a php error and I knew which file it was but I couldn't find the missing piece till I went back and re-read the payment module install docs.