title: Downloading a CSV opens up in Web Browser not on a Microsoft Excel
body: <p>I am using CakePHP on performing this code:</p>
  
  <p>View File</p>
  
  <pre><code>&lt;?php
     if (isset($csv_filename)) {
        header("Content-Disposition: attachment; filename=$csv_filename");
     }
  ?&gt;
  &lt;?=$csv?&gt;
  </code></pre>
  
  <p>When I run this page and download the file(Open With), it is opening up on a web browser such as Google Chrome or Firefox. I wanted this file to be opened using 
  <img src="https://i.stack.imgur.com/kimyE.png" alt="enter image description here"></p>
  
  <p><strong>My expected output should be like this:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/BGsq4.png" alt="enter image description here"></p>
  
  <p>Actually, everything was working fine before since we migrated to CakePHP 2.2.2.</p>
  
  <p>Any thoughts on this, your help will be greatly appreciated! Thanks :)</p>