authorize.net AIM description field

I would like the description field in the authorize.net transaction populated with the product description or product item number. How can I do this?

Thanks for your help.

Thanks!

We're not getting product code or any product info about the order in our auth.net receipt (I have not made any changes to the authorize.php file). We just get this:
========= GENERAL INFORMATION =========

Merchant : ABC (12345)
Date/Time : 23-Aug-2011 06:46:37 AM

========= ORDER INFORMATION =========
Invoice :
Description :
Amount : 42.00 (USD)
Payment Method : MasterCard
Type : Authorization and Capture

============== RESULTS ==============
Response : This transaction has been approved.
Authorization Code : 012345
Transaction ID : 1234567
Address Verification : Street Address: Match -- First 5 Digits of Zip: Match

==== CUSTOMER BILLING INFORMATION ===
Customer ID :
First Name : John
Last Name : Smith
Company :
Address : 123 Main St.
City : New York
State/Province : New York
Zip/Postal Code : 22222
Country : United States of America
Phone : 555-1212
Fax :
E-Mail : This email address is being protected from spambots. You need JavaScript enabled to view it.

==== CUSTOMER SHIPPING INFORMATION ===
First Name : John
Last Name : Smith
Company :
Address : 123 Main St.
City : New York
State/Province : New York
Zip/Postal Code : 22222
Country : United States of America

======= ADDITIONAL INFORMATION ======
Tax :
Duty :
Freight :
Tax Exempt : Yes
PO Number :

ok.
I found this info from authorize.net site about the x_line_item array:
Based on their respective business requirements, merchants can choose to submit itemized order information with a transaction. Itemized order information is not submitted to the processor and is not currently returned with the transaction response. This information is displayed on the Transaction Detail page and in QuickBooks download file reports in the Merchant Interface.

So I decided to add code to get the x_description field to show order info to the authorize.php file:
Added this line: $vars["x_description"]=""; before the loop
Then added this line after $vars["x_line_item"]...:
$vars["x_description"]=$vars["x_description"].'Product Code: '.$product->order_product_code.', Product Name: '.$product->order_product_name.', Quantity: '.$product->order_product_quantity.', Price: '.round($product->order_product_price,(int)$currency->currency_locale).'\r\n';

This code adds product order info to the authorize.net receipt by filling the x_description field. However, the Product Code is not coming through, but rather, the product code is the same as the product name. Is there something I'm doing wrong?

Full code snippet below:

		$vars["x_description"]="";
		$vars["x_line_item"]=array();
		foreach($order->cart->products as $product){
			if(bccomp($product->order_product_tax,0,5)){
				$tax+=$product->order_product_quantity*round($product->order_product_tax,(int)$currency->currency_locale['int_frac_digits']);
				$has_tax = 'TRUE';
			}else{
				$has_tax = 'FALSE';
			}
			$vars["x_line_item"][]=substr($product->order_product_code,0,30).'<|>'.substr(strip_tags($product->order_product_name),0,30).'<|><|>'.$product->order_product_quantity.'<|>'.round($product->order_product_price,(int)$currency->currency_locale['int_frac_digits']).'<|>'.$has_tax;
			$vars["x_description"]=$vars["x_description"].'Course Number: '.$product->order_product_code.', Course Name: '.$product->order_product_name.', How many signups: '.$product->order_product_quantity.', Price: '.round($product->order_product_price,(int)$currency->currency_locale['int_frac_digits']).'\r\n';
		}

Ok. I checked and yes it is working. Thanks.

I checked this code,it really works great...

Same problem for me, details not supplied on Merchant Email Receipt. Authorize.net says:

If you need the Description details listed in the Merchant Email Receipt, your web developer will need to adjust your website/shopping cart so that Itemized Order Information is no longer being used.

I am trying to implement code from mrdan, he says:

Added this line: $vars["x_description"]=""; before the loop

Then added this line after $vars["x_line_item"]...: