What's the best way to integrate DNN with the PayPal shopping cart?

I have a DNN e-commerce site that I want to integrate with the PayPal shopping cart. Other systems depend on the PayPal shopping cart, so I can't use my own. I have tried linking 'Add to Cart' buttons that pass product information to the PayPal cart, but I've run into the following problems:

-- PayPal's recommended method is to create a form with hidden input fields that contain the product information associated with each 'Add to Cart' button. The button submits the hidden form. This doesn't work, because DNN doesn't allow forms in the text/html module.

-- PayPal says in that case, submit product information using an <a> tag and a query string. For security reasons, I don't want to do that--it looks to me like just asking for trouble.

I've looked at several forms modules, but I'm not sure any of these will really do what I need.

Has anyone else run into this problem? Can anyone give me any suggestions on how to address it? Thanks.

I found my answer in the post John Mitchell refers to in his reply to my original message. Here is John's solution, from his earlier message:

You can do this with a simple javascript trick.

Step 1. Remove the <Form> </Form> tags from your PayPal "Buy Now" code.
Step 2. Add onClick="document.getElementById('Form').action='https://www.paypal.com/cgi-bin/webscr';" to the buy now input button

Step 3. paste all of it into the html module


Note: older versions (1.0x) of DNN had the Form name as Form1 so step #2 would be
Add onClick="document.getElementById('Form1').action='https://www.paypal.com/cgi-bin/webscr';" to the buy now input button

I had this working the other day, but now I'm getting an error: Here is the error I'm getting:

"'document.getElementById(...)' is null or not an object"

And here is the markup that I am using:

<input type="image" src="https://www.paypal.com/en_US/i/btn/x-click-but22.gif" border="0" name="submit" alt="Add to Cart" onClick="document.getElementById('Form').action='https://www.paypal.com/cgi-bin/webscr';">
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
<input type="hidden" name="add" value="1">
<input type="hidden" name="cmd" value="_cart">
<input type="hidden" name="business" value="johndoe@mycompany.com">
<input type="hidden" name="item_name" value="My Product">
<input type="hidden" name="item_number" value="MP1">
<input type="hidden" name="amount" value="99.00">
<input type="hidden" name="no_shipping" value="1">
<input type="hidden" name="return" value="http://mycompany.com">
<input type="hidden" name="cancel_return" value="http://mycompany.com">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="lc" value="US">
<input type="hidden" name="bn" value="PP-ShopCartBF">

Any thoughts as to what I'm doing wrong? Thanks again for your help!

David Veeneman
Foresight Systems