Got it - x_test_request
Sorry Ray . . . figured it out. I need to slow down a little bit:)
1. In confirm.php, open Code View.
2. About line 149 or so, you should see this line:
$AuthNet_required[$nextIndex] = "x_test_request";
$AuthNet_required[$nextIndex] = "TRUE";
3. Change the "TRUE" value to "FALSE"
Again, feel free to post questions here and I will be glad to share what I have learned from Ray and reading about eCart and Authorize.net thus far.