title: PHP: Appending (adding) html content to exsisting element by ID
body: <p>I need to search for an element by ID using PHP then appending html content to it. It seems simple enough but I'm new to php and  can't find the right function to use to do this.</p>
  
  <pre><code>$html = file_get_contents('http://example.com');
  $doc = new DOMDocument(); 
  libxml_use_internal_errors(true);
  $doc-&gt;loadHTML($html);
  $descBox = $doc-&gt;getElementById('element1');
  </code></pre>
  
  <p>I just don't know how to do the next step. Any help would be appreciated.</p>