title: The download doesn't work as expected. I'm a beginner in php
body: <p>I have a problem. I made a little download code. All i'm getting is a blank page.
  Url to download: <a href="https://jonasgamertv.com/download.php?file=header.png" rel="nofollow noreferrer">https://jonasgamertv.com/download.php?file=header.png</a>
  This is my code:</p>
  
  <pre><code>&lt;?php
  if(isset($_REQUEST["file"])){
  
      // Get parameters
      $images = array("header.png");
      $file = urldecode($_GET["file"]); // Decode URL-encoded string
  
      if(in_array($file, $images, true)){
          $filepath = "../images/" . $file;
  
          // Process download
          if(file_exists($filepath)) {
              header('Content-Description: File Transfer');
              header('Content-Type: application/octet-stream');
              header('Content-Disposition: attachment; filename="'.basename($filepath).'"');
              header('Expires: 0');
              header('Cache-Control: must-revalidate');
              header('Pragma: public');
              header('Content-Length: ' . filesize($filepath));
              flush(); // Flush system output buffer
              readfile("$filepath");
              exit;
          }
      }
      else{
          echo "File does not exist.";
      }
  }
  ?&gt;
  </code></pre>
  
  <p>Thanks for your help and time,
  Jonas</p>