magpierss in postbit

[Blackhat]

Im trying to list the latest published article in each users postbit. Im using magpierss to pull the feed from wordpress and this is the code I got

PHP Code:

$rss = fetch_rss("http://www.domian.com/author/".$userinfo[username]."/feed" );
foreach ($rss->items as $item) {
        $wpLink = $item[0]['link'];
        $wpTitle = $item[0]['title'];
    } 


but I suspect the $userinfo[username] part dont work inside a plugin, so how can I fix this ?

(The wordpress author name and forum username is the same)