Error message whenever I open the index.php page
<p>I'm working on a website and this is what I have for my index.php:</p>

<pre><code> &lt;?php

    $p     = $_GET['p'];
    $pages = array('home', 'culture', 'design', 'art', 'about');
    $path  = 'http://localhost:8080/projects';

    include('header.php');


    if(!isset($p) || !in_array($p, $pages)) {
        include('header.index.php');
        include('content.index.php');
    } else {
        switch($p) {
            case "home";
                include('header.home.php');
                include('content.home.php');
            break;
            case "culture";
                include('content.culture.php');
            break;
            case "design";
                include('content.design.php');
            break;
            case "about";
                include('content.about.php');
            break;
            case "art";
                include('content.art.php');
            break;
            default:
                include('content.index.php');
            break;
        }
    }
    include('footer.php');
    ?&gt;
</code></pre>

<p>I get the following error:</p>

<pre><code>**Notice: Undefined index: p in C:\wamp\www\projects\index.php on line 3
Call Stack
#   Time    Memory  Function    Location
1   0.0523  680200  {main}( )   ..\index.php:0**
</code></pre>
