title: Create one function to check if user logged in php
body: <p>I want to create a function that will check if the user is logged in. If so, the user should be navigated to userActive, otherwise the loginForm should be displayed.</p>
  
  <p>I also want to carry out a check on the loginForm page to check if the user is logged in. If so, they should be taken to userActive, or kept on the loginForm page.</p>
  
  <p>Why issue is why the following code doesn't work. I keep hitting a loop.</p>
  
  <pre><code>$_COOKIE['user_id'] = "user_id: 1";
  
  activeUser();
  
  function activeUser()
  {
      if($_COOKIE['user_id'] == "user_id: 1")
      {
          header('location: index.php?a=activeUser');
      }
      else
      {
          header('location: index.php?a=loginForm');
      }
  }
  
  switch($_GET['a'])
  {
      case 'loginForm':
          include_once('loginForm.php');
      break;
  
      case 'activeUser':
          include_once('activeUser.php');
      break;
  }
  </code></pre>