title: magento load phtml in admin
body: <p>First sorry for my realy bad english.</p>
  
  <p>I'm tryng to study magento.
  The problem is load PHTML file in admin panel.
  In menu the link is ok but I load a blank page.
  The BLOK is ok becaus if I load in font and it's OK.</p>
  
  <p>This is my file:</p>
  
  <p><strong>/app/code/local/Package/HelloWorld/etc/config.xml</strong></p>
  
  <pre><code>  &lt;admin&gt;
          &lt;routers&gt;
              &lt;helloworld&gt;&lt;!-- nome modulo --&gt;
                  &lt;use&gt;admin&lt;/use&gt;
                  &lt;args&gt;
                      &lt;module&gt;Package_HelloWorld&lt;/module&gt; &lt;!-- namespace --&gt;
                      &lt;frontName&gt;admintest&lt;/frontName&gt;&lt;!-- path--&gt;
                  &lt;/args&gt;
              &lt;/helloworld&gt;
          &lt;/routers&gt;
      &lt;/admin&gt;
      &lt;adminhtml&gt;
          &lt;layout&gt;
              &lt;updates&gt;
                  &lt;helloworld&gt;
                      &lt;file&gt;helloworld.xml&lt;/file&gt;&lt;!-- file di layout, ricordiamoci che sta in /app/design/adminhtml/default/--&gt;
                  &lt;/helloworld&gt;
              &lt;/updates&gt;
          &lt;/layout&gt;
          &lt;menu&gt;&lt;!-- aggiungo al menu del pannello--&gt;
              &lt;helloworld translate="title" module="adminhtml"&gt;
                  &lt;title&gt;The Nano &lt;/title&gt;
                  &lt;sort_order&gt;100&lt;/sort_order&gt;
                  &lt;children&gt;
                      &lt;set_time&gt;
                          &lt;title&gt;Leggo da db&lt;/title&gt;
                          &lt;action&gt;admintest/adminhtml_index&lt;/action&gt;
                      &lt;/set_time&gt;
                  &lt;/children&gt;
              &lt;/helloworld&gt;
          &lt;/menu&gt;
      &lt;/adminhtml&gt;
  </code></pre>
  
  <p><strong>/app/design/adminhtml/default/Package/layout/helloworl.xml</strong></p>
  
  <pre><code>&lt;layout version="0.1.0"&gt;
      &lt;helloworld_adminhtml_index_index&gt;
          &lt;default name="content"&gt;
              &lt;block type="nomeblocco/nomebloccointerno" name="helloworld_scheda"    template="helloworld/scheda.phtml"/&gt;
          &lt;/default&gt;
      &lt;/helloworld_adminhtml_index_index&gt;
  &lt;/layout&gt;
  </code></pre>
  
  <p>the PHTML is ok and is:</p>
  
  <p><strong>/app/design/adminhtml/default/Package/template/helloworl/scheda.phtml</strong></p>