title: Insert attribute in a <html> line
body: <p>I wan to insert this line of code:</p>
  
  <pre><code>xml:lang="&lt;?php echo $this-&gt;language; ?&gt;" lang="&lt;?php echo $this-&gt;language; ?&gt;"
  </code></pre>
  
  <p>to this line of code:</p>
  
  <pre><code>&lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  </code></pre>
  
  <p>so the output is like this:</p>
  
  <pre><code>&lt;html xmlns="http://www.w3.org/1999/xhtml" 
  xml:lang="&lt;?php echo $this-&gt;language; ?&gt;" lang="&lt;?php echo $this-&gt;language; ?&gt;" &gt;
  </code></pre>
  
  <p>I'm using this: <a href="http://simplehtmldom.sourceforge.net/" rel="nofollow">Simple DOM Parser</a></p>
  
  <p>when use this:</p>
  
  <pre><code>$html-&gt;find('html', 0)-&gt;outertext = '&lt;html xmlns="http://www.w3.org/1999/xhtml" 
  xml:lang="&lt;?php echo $this-&gt;language; ?&gt;" lang="&lt;?php echo $this-&gt;language; ?&gt;" &gt; ';
  </code></pre>
  
  <p>The whole HTML file will be lost and will be replaced by the code above. It's getting all the outertext of HTML.
  But I just want to change the line of HTML code.</p>