why can't reload httpd server or other ?

[Anon]

<?
$com="su -l root -c \"etc/rc.d/init.d/httpd reload\"";
$rootpw="mypass";
$fp=popen($com,"w");
fputs($fp,rootpw);
flclose($fp)
?>
exec simple but can't successed.
Why??
Please help?
email:[e-mail]

[Anon]

Tried running it from the server's account's command prompt? (How easy is it for "nobdoy" to su to "root"?)