Why two different URLs then?
Why have two different URLs then to the same ad page from one query results page? One of my points is that if you need to pass the category variable, then pass it consistently from the same query results page. For example, on "Last 7 Day" query results page, the thumbnail currently passes a specific catid, but the text link passes "all". If this is intended to produce different results in the showproduct script, wouldn't that be confusing for the user?
No matter how I try to come into the showproduct.php script, the prev/next only seem to show ads for the immediate category. If this is the case consistently across the system then passing the category to the showproduct script seems unnecessary. I'm doing my best to understant here.