Hi.  I'm evaluating the SmithCart for purchase.  I've read the page in the user manual on the Custom Web Service Gateway (pg 41), and I know what the parameter names are that this gateway option requires back from the POST (AuthCode, Status, TransID, Notes, Amount). 

My question is, what format does this gateway option expect these return parameters to be in?  I tried returning this simple XML without success:

<?xml version="1.0" encoding="utf-8" ?>
<CartResponse>
     <AuthCode>APPROVED</AuthCode>
     <Status>SALE/APPROVED</Status>
     <TransID>ABC123</TransID>
     <Notes>This is a test.</Notes>
     <Amount>55.44</Amount>
</CartResponse> 

Thanks Scott!  That's exactly the information I needed. Works like a charm.  Here's some sample code passing the reply back:

string myResponse = "AuthCode=APPROVED&Status=APPROVED&TransID=ABC123&Amount=11.22&Notes=This is a test.&";

Response.Clear();
Response.ContentType = "text/plain";
Response.Write(myResponse);
Response.End();