title: Its getting logout, but session not getting expire
body: <p>The below one is the link in my php site.. after clicking this button the user's session should be terminated and came to login page.</p>
  
  <p>But the session not getting expire.</p>
  
  <pre><code>&lt;?php
  $logoutGoTo = "../index.php";
  if (!isset($_SESSION)) {
    session_start();
  }
  $_SESSION['MM_Username'] = NULL;
  $_SESSION['MM_UserGroup'] = NULL;
  $_SESSION['PrevUrl'] = NULL;
  unset($_SESSION['MM_Username']);
  unset($_SESSION['MM_UserGroup']);
  unset($_SESSION['PrevUrl']);
  if ($logoutGoTo != "") {header("Location: $logoutGoTo");
  exit;
  }
  ?&gt;
  </code></pre>