Popup window advice needed
I'm in the process of updating/unobtrusifying my gallery website.
The html for the thumbnail links is generated in PHP from a database.
I need to pass an identifier to popup.php and wondered if it was 'a okay' to add a 'picId' property to my html as follows and then construct a URL something along the lines of 'popup.php?imageId=' + imgLink[x].getAttribute('picId').
Is the above idea a bad idea semantically or just a bad idea fullstop.
<a href="ASSETS/Hires/Torosaurus.jpg" picId="1">
<img src="ASSETS/Thumbs/Torosaurus.jpg" alt="Torosaurus"