title: Insert element in XHTML
body: <p>I have a problem in XHTML, I tested this code in HTML and work it.</p>
  
  <p><strong>index.xhtml</strong></p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
      &lt;head&gt;
          &lt;title&gt;jQuery Load&lt;/title&gt;
          &lt;!-- Libreria jQuery --&gt;
          &lt;script type='text/javascript' src="js/jquery-1.11.1.min.js"&gt;&lt;/script&gt;
          &lt;script type="text/javascript"&gt;
              $(document).ready(function() {
                  $("#botton").click(function(event) {
                      $("#cap").load('test.xhtml #content');
                  });
              });
          &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;div id="cap"&gt;Click here...&lt;/div&gt;
      &lt;br/&gt;
      &lt;input id="botton" type="button" value="update" /&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>test.xhtml</strong></p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
      &lt;head&gt;
          &lt;title&gt;Content&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
        &lt;div id="content"&gt;Show content, YES.&lt;/div&gt;
        &lt;div id="hidden"&gt;I don't show&lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>This XHTML no work it. error console:</p>
  
  <p><strong>Uncaught SyntaxError: Failed to set the 'innerHTML' property on 'Element': The provided markup is invalid XML, and therefore cannot be inserted into an XML document.</strong> </p>
  
  <p>HTML works, but does not work in XHTML, right is valid XHTML insert elements?, thank you all.</p>