Hi I tried sending a new message but it didn't show up. I'll try again.

I'm looking for any kind of ideas for adding a popup box on confirmation of a purchase with an open source online store script.

I've messaged on their bulletin board but they're not responding.

I've tried this code as a test and it works on click. However I cannot add or format any other text verbiage or email link. I'm not looking for any special kind of effects. Just a message box with a close button and allows html. The PHP code has no head tags either. Which makes it harder because practically all of the scripts require adding the javascript to the head and a form to the body.

Code:
echo "<script type='text/javascript'>alert('Really annoying pop-up!');</script>";
Thank you ahead of time for any help. It's greatly appreciated.