[Duramax 6.6L]

Please move this message if I posted to wrong forum.

I am trying to change the registration form to allow capital letters. I changed the following line in include/register.php but it does not work.

From:
if ((strcmp($uname_tmp, $uname) != 0) || (!preg_match("/^[a-z0-9_-]+$/s", $uname) && $uname != ""))

To:
if ((strcmp($uname_tmp, $uname) != 0) || (!preg_match("/^[a-zA-Z0-9_-]+$/s", $uname) && $uname != ""))

when registering an admin or customer, it still displays the error message that only lower case letters and numbers may be used.