GET Requests and Redirect in PHP

During a redirect, you can also pass GET parameters:

php<?php
  header('Location: test.php?arg=1');
?>
Задание 1

Let it be possible to pass a GET parameter named success on the page index.php. Make it so that if such a parameter is present, a success message is displayed on the page.

Задание 2

Now create the page action.php. Let visiting this page trigger a redirect to the page index.php from the previous task. During the redirect, pass the value 1 in the GET parameter success.