Ok i am making a forum, and it allows unlimited sub-forums. How my db is set up, it is has a parentforumID for the parent forum of that forum. (duh).

If there is no parent forum then it is equal to 0. So i need to do a breadcrumb for this, and i tried using a while loop, but it doesnt seem to work.

What am i doing wrong?

PHP Code:
if ($forums->forumExists($_GET['forumid'])) {
    $catID = $forums->getCategoryID($_GET['forumid']);
    $catname = $forums->getCategoryName($catID);
    $forumname = $forums->getForumName($_GET['forumid']);
    $breadcrumb = "&gt; <a href='?action=home#cat_{$catID}'>{$catname}</a> ";
    $forumID = mysql_real_escape_string($_GET['forumid']);
    $sql1 = "SELECT `parentforumID` FROM `".$db_prefix."forums` WHERE forumID='{$forumID}' LIMIT 1";
    $query1 = mysql_query($sql1);
    $res1 = mysql_fetch_array($query1);
    if ($res1['parentforumID'] == 0) {
        $breadcrumb .= "&gt; {$forumname}";
    } else {
        $parentID = $res['parentforumID'];
        while ($parentID!=0) {
            $sql = "SELECT     `parentforumID` FROM `".$db_prefix."forums` WHERE forumID='{$parentID}' LIMIT 1";
            $query = mysql_query($sql) or die(mysql_error());
            $res = mysql_fetch_array($query);
            $name = $forums->getForumName($parentID);
            $breadcrumb .= "&gt; <a href='?action=viewforum&forumid={$parentID}'>{$name}</a> ";
            $parentID = $res['parentforumID'];
        }
    }
} else {
    $breadcrumb = "&gt; Error";
}