LYCUK, попробуй так
$total = mysql_result(mysql_query("select count(*) from `forum` join `cms_forum_files` on cms_forum_files.del=0 and forum.id=cms_forum_files.post and forum.from='" . $_GET['list'] . "'"), 0);
echo $total;
LYCUK, попробуй так
$total = mysql_result(mysql_query("select count(*) from `forum` join `cms_forum_files` on cms_forum_files.del=0 and forum.id=cms_forum_files.post and forum.from='" . $_GET['list'] . "'"), 0);
echo $total;