Need help with authorize.net sim gateway

1.3.8, I haven't upgraded yet.

I have been searching this website for the last 4 days now and can't seem to find what I am looking for.

I have just recently set up a shopping cart using Zen Cart 1.3.8 and my payment gateway is authorize.net sim. everytime there is an order placed, and I check it through Authorize.net, there is no invoice number, which makes it tough when printing out multiple orders to be shipped. Can someone please help me out, I have tried to edit the authorizenet.php 'x_invoice_num' => $_SESSION['customer_id'], and now I get a customer number in the place of the invoice number. What I need is it to automatically update the invoices each time an order is placed, for instance, order #1, order #2, etc.

Thank you for your help.

The AIM module already does that.
Also, the AIM module is much more secure in that it prevents the possibility of customers stealing your authnet account details and prevents them from spoofing transaction confirmations like they could do with the SIM module.

I understand that, but at this point I am using the SIM. Is there any way you can tell me how to make it work? It does not automatically do it through authorize.net sim.

You could copy the some code from the AIM module into your SIM module. It's only an approximation as the order number can only be guessed since the real number is never assigned until after payment is completed.

can you let me know what I should do? below are both codes the sim and aim. I have updated the sim to do the customer number, but I can't keep having duplicate orders from the same customer.

authorize.net sim=
'x_invoice_num' => $_SESSION['customer_id'],

Authorize.net AIM=
'x_invoice_num' => (MODULE_PAYMENT_AUTHORIZENET_AIM_TESTMODE == 'Test' ? 'TEST-' : '') . $new_order_id,

Just a simple question,

Is there a reason that you would be required to use the less secure SIM over the AIM module?

That is what I am being told to use by the company. I didn't help set up the merchant services, I am only trying to help them out and build them a shopping cart that works, compared to their old one.

I made a mistake when asking my question earlier; what I meant to say is that they currently have a shopping cart running that is using authorize.net sim and they would like to continue where they have left off with the invoice numbers. Can you please let me know what I need to edit in order for that to happen? They would like to start off with invoice number 3230. I apologize for my mistake.

I greatly appreciate any help that can be provided.

Thanks,

Kevin

Change the next order number via Admin->Tools->Store Manager