PHP if "id" null move to url
<p>Need assistance with the following code, i have a form providing a "id", when submitted the next script gets the data from the database, if for some reason the "id" is zero, how can i forward the url to my 404 page.</p>

<p>Code:</p>

<pre><code>$id=$_GET['id'];
        include ('dbconnection.php');
        include ('dbopen.php');
        include ('header.php'); 
</code></pre>

<p>I have tried the following, but no success to move client to the 404.php page if "id" value is null.</p>

<pre><code>if (isset($_GET['id']) &amp;&amp; !empty($_GET['id'])) {

  header('Location: index.php');
}
</code></pre>

<p>Please help :D</p>
