Currently, I have Lightbox 2 working in the classical way, i.e. a link to an image (in my case it is a script, i.e. photo.php?id=123) with a rel="lightbox" attribute.
I would like Lightbox to add by itself a parameter to the picture URL, so that photo.php?id=123 becomes for example photo.php?id=123&viewer=lightbox
Again, Lightbox should add the parameter by itself, I do not want to put that parameter in the page from which Lightbox is called.
Is that possible and what part of the lightbox code should I tweak?