logout in php

dashboard.php

<?php

session_start();
if(!isset($_SESSION['user_id'])) {
	header("location: logn.html");
	exit;
}

echo "Welcome to your dashboard";

?>

<form action="logout.php">
	<button>Logout</button>
</form>

logout.php

<?php

session_start();
session_destroy();
header("Location: login.html");