The integration is done with the tracking code inserted to your "thank you" page.

1.

Adding the sale tracking script

Virtual Merchant send these GET variables to your site:
ssl_description -> can be used as order id
ssl_amount stands -> stands for total cost
ssl_invoice_number -> can be used as product id

Insert this code to your thank you page:

<script type="text/javascript">
	document.write(unescape("%3Cscript id=%27pap_x2s6df8d%27 src=%27" + (("https:" == document.location.protocol) ? "https://" : "http://") + "URL_TO_PostAffiliatePro/scripts/trackjs.js%27 type=%27text/javascript%27%3E%3C/script%3E"));
</script>
<script type="text/javascript">
	function gup( name ) {
	  name = name.replace(/[[]/,"\[").replace(/[]]/,"\]");
	  var regexS = "[\?&]" name "=([^&#]*)";
	  var regex = new RegExp( regexS );
	  var results = regex.exec( window.location.href );
	  if( results == null )
	    return "";
	  else
	    return results[1];
	}
	
	
	var sale = PostAffTracker.createSale();
	sale.setTotalCost(gup('ssl_amount'));
	sale.setOrderID(gup('ssl_invoice_number'));
	sale.setProductID(gup('ssl_description'));
	PostAffTracker.register();
</script>

This is all what you need to do in case of the integration.