preg_match_all Issues

[Immortal]

if(THIS_SCRIPT == 'forumdisplay' OR THIS_SCRIPT == 'showthread' OR THIS_SCRIPT == 'index')
{
preg_match_all('/<a href="forumdisplay\.php\?f=([0-9]+).*?">(.*?)<\/a>/i', $GLOBALS['navbits']['breadcrumb'], $rewritten);


$query_dataset = $vbulletin->db->query_first("SELECT forumid,title FROM forum WHERE forumid='".$rewritten[0][1]."'");

$output = strtolower(str_replace("forumdisplay.php?f=","f-{$query_dataset['title']}-{$query_dataset['forumid']}.html",$output));
}


Yet it's not rewriting any of my URLs. Anyone have any suggestions?

Thanks to Chroder, I was able to solve it.

(/me will share the code when/if he releases his plugin)