[TYPO3-english] typoscript configuration issue

[tom liu]

1. In typo3conf/ext/feuserstat/static/frontend_user_list/setup.txt, the
code is like this:
plugin.tx_feuserstat_pi1 = USER
plugin.tx_feuserstat_pi1 {
    # uid of the page where Frontend user records are stored
    usersPid = 29
    # uid of the page where single view is located
    singlePid = 10
...

2. in tempalte->includes->include static(from extensions), I add Frontend
user list(feuserstat)
3. in In typo3conf/ext/feuserstat/pi1/class.tx_feuserstat_pi1.php, I have
such code:
...
    public function main($content, $conf) {
        $this->conf = $conf;
            $this->pi_setPiVarDefaults();
        $this->pi_loadLL();

        // Check environment
        if (!isset($conf['usersPid'])) {
            return
$this->pi_wrapInBaseClass($this->pi_getLL('no_ts_template'));
        }
...
When I run this extension, It always shows 'no ts template', and
var_dump($conf['usersPid']),result is null, so
somehow the typoscript setup.txt does not work properly. BTW, under
template->general->setup, there is no other
typoscripts there.
so what could be the problem?