Thank you Fou-LU for replling. You are the first in over 120 views. Let me first say this is using WordPress.
I tried to echo some of the values and also did var_dump() but they were NULL. The $URL2 part I accidentally left in there. I have tried may different things to get results.
$status = $Response->getElementContent('messages'); always was empty so it printed that error "A configuration error occurred while processing this ...."
The error messages get fed to MYCART_TRXN_ERR. That is what I referred to as the message box.
There is a back end part of the store that tracks the purchases. Next to each one it lists if it was PENDING or PURCHASED and records the tranaction ID. I think $txnstatus = $this->status[$status]; this section saves the purchases. But as I have it now it just takes the values, sends them in XML to Authorize.Net and bypasses the whole system.
How can I do file logging? What other ways can I get more errors or results to show?