title: How to get the whole content of a html div in lua
body: <p><strong>EDIT</strong> : I have found how to post headers, and I know how to get the value, but need help to do it. Here is it.</p>
  
  <ul>
  <li>I have to retrieve the webpage. (this part is ok)</li>
  <li>Find on which line result "formulaire_action_args" appears and save it in a variable. (looking for a better way than a loop to do it)</li>
  <li>And retrieve the attribute "value" from this line.</li>
  </ul>
  
  <p>I am trying to get the content of an html page contained in a div like so:</p>
  
  <pre><code>&lt;form id="formulaire_login" method="post" action="/spip.php?page=login&amp;amp;lang=fr" enctype="multipart/form-data"&gt;
      &lt;div&gt;
          &lt;input name="page" value="login" type="hidden"&gt;
          &lt;input name="lang" value="fr" type="hidden"&gt;
          &lt;input name="formulaire_action" type="hidden" value="login"&gt;
          &lt;input name="formulaire_action_args" type="hidden" value="random_value"&gt;
      &lt;/div&gt;
      &lt;fieldset&gt;
          &lt;ul&gt;
              &lt;li class="editer_login obligatoire"&gt;
                 &lt;input type="text" class="text" name="var_login" id="var_login" value="" size="40"&gt;
              &lt;/li&gt;
              &lt;li class="editer_password obligatoire"&gt;
                  &lt;input type="password" class="password" name="password" id="password" value="" size="40"&gt;
              &lt;/li&gt;
          &lt;/ul&gt;
      &lt;/fieldset&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I want to get the content of form with id="formulaire_login" and inside this form get the value of the attribute "value" (random_value) of the input</p>
  
  <pre><code>&lt;input name="formulaire_action_args" type="hidden" value="random_value"&gt;
  </code></pre>
  
  <p>And on a second hand, I am looking for a way to request a URL with POST header data.</p>