daniel22222 on "custom login page only allowing admin login"

I created a custom login page, but it only seems to allow me to login as the admin. My blog allows people to signup and comment on posts, but this login page does not allow normal users to login. Is there a different function for this purpose?

if($_POST){
//We shall SQL escape all inputs
$username = $wpdb->escape($_REQUEST['username']);
$password = $wpdb->escape($_REQUEST['password']);
$remember = $wpdb->escape($_REQUEST['rememberme']);

if($remember) $remember = "true";
else $remember = "false";
$login_data = array();
$login_data['user_login'] = $username;
$login_data['user_password'] = $password;
$login_data['remember'] = $remember;
if ($username == "" || $password == "") {
	if ($username == "") {
		echo "<b>ERROR:</b> Invalid username.";
		exit();
	} else {
		echo "Login failed, your password cannot be left blank.";
		exit();
	}
}
$user_verify = wp_signon( $login_data, true);
//var_dump($user_verify);
//exit();
if ( is_wp_error($user_verify) )
{

   echo  "<span class='error'>".$user_verify->get_error_message()."</span>";
   exit();
 } else
 {
   echo "<script type='text/javascript'>window.location='". get_bloginfo('url') ."'</script>";
   exit();
 }
}