thanks
on the results page am not sure how to structure the filter and have tried a variety with no luck:
$SubCategory->setQuery("SELECT * FROM gallery_category_contents WHERE ProductContentsID = ? AND CategoryID <> 0");
$SubCategory->bindParam("i", "".(isset($_GET['CategoryID'])?$_GET['CategoryID']:"") ."", "-1"); //colname
and
$SubCategory->setQuery("SELECT * FROM gallery_category_contents WHERE CategoryID = ? AND CategoryID <> 0");
$SubCategory->bindParam("i", "".(isset($_GET['ProductContentsID'])?$_GET['ProductContentsID']:"") ."", "-1"); //colname
and also
$SubCategory->setQuery("SELECT * FROM gallery_category_contents WHERE CategoryID = ProductContentsID");
