登录用户重定向取决于列值PHP

Question

I have a script below which redirects non logged in users to the logout page, which works ok for users not logged in. The table this accesses is called 'users'.

What I am trying to do however, is redirect logged in users whose data in the 'users_type' does not match the query below. For instance, if their 'users_type' data is 'Admin', it will redirect the page to the logout area. Any ideas?

    <?php 
    require_once ('config.inc.php');
    $page_title = 'Page Title';
    include ('header.html');
    if (!isset($_SESSION['users_type']) == 'Sales') {
       $url = 'http://' . $_SERVER['HTTP_HOST']
        . dirname($_SERVER['PHP_SELF']);
       if ((substr($url, -1) == '/') OR (substr($url, -1) == '\\') ) {
            $url = substr ($url, 0, -1); 
       }
       $url .= 'logout.php'; 
    ob_end_clean(); 
    header("Location: $url"); 
    exit(); 
    }
    ?>

EDIT: This code works

    <?php 
    require_once ('config.inc.php');
    $page_title = 'Page Title';
    include ('header.html');
    if(isset($_SESSION['users_type']) && $_SESSION['users_type'] != 'Sales')    {
    $url = 'http://' . $_SERVER['HTTP_HOST']
     . dirname($_SERVER['PHP_SELF']);
       if ((substr($url, -1) == '/') OR (substr($url, -1) == '\\') ) {
            $url = substr ($url, 0, -1); 
       }
       $url .= 'logout.php'; 
    ob_end_clean(); 
    header("Location: $url"); 
    exit(); 
    }
    ?>

Answer 1

Change

if (!isset($_SESSION['users_type']) == 'Sales') 

To

if (isset($_SESSION['users_type']) && $_SESSION['users_type'] == 'Sales')