If you think you’ve received a suspicious email or have been directed to a fake website, forward it to email@example.com and we’ll investigate it for you. After you send us the email, delete it from your inbox. If you clicked on any links or downloaded any attachments within the suspicious email or website, log into your account and view your transactions. It’s also a good idea to change your password.
You have great request, however PayPal does have a Developer Forum that would be able to better assist you with setting up your shopping cart with a joomla 1.5 web site selling t-shirts. Here is a direct link. I hope this will help.