Need help

Ok, I have photppost installed. What I want to do is check whether the post user has any pics in the photos table, if do, show an icon to those pics.

I have tried this in showthread.php right before
// display ratings if enabled

PHP Code:

$myride2=$DB_site->query_first("select postuserid from thread WHERE threadid='$threadid'");
  $postuserid2=$myride2[postuserid];
    $myride=$DB_site->query_first("SELECT id FROM  photos  WHERE userid = '$postuserid2'");    
        $showmyride = $DB_site->num_rows($myride); 

And I am using Logicians dynamic template hack to show the img, but I get an error that the num_rows is not a valid result resource.

Any ideas?

Thanks,
Derek