title: If GET isn't ... or if GET is empty
body: <p>I want to add <code>class sidebg</code> when the user doesn't visit the page 'wijzigpagina' or if the <code>$_GET page</code> is empty.</p>
  
  <p>I tried adding <code>&amp;&amp; empty($_GET["page"])</code>:</p>
  
  <pre><code>&lt;div id="wrapper"&lt;?php if(isset($_GET["page"]) &amp;&amp; $_GET["page"] !== "wijzigpagina" &amp;&amp; empty($_GET["page"])) { echo ' class="sidebg"'; } ?&gt;&gt;
  </code></pre>
  
  <p>But that didn't work.</p>