title: Prototype: Element.getDimensions(k[0]).height return 0
body: <p>I have a ul list:</p>
  
  <pre><code>&lt;ul&gt;
      &lt;li class="cl1"&gt;example&lt;/li&gt;
      &lt;li class="cl2"&gt;example&lt;/li&gt;
      &lt;li class="cl3"&gt;example&lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I'm trying to get height of each li element:</p>
  
  <pre><code>k = $$('li.cl1');
  el = k[0];
  
  Element.getDimensions(el).height - return 0
  or
  el.getDimensions().height - return 0
  </code></pre>
  
  <p>If I take a height of some div then its ok. What's wrong here?</p>
  
  <p>PS: I found my fault: when the page has been loaded li css has display:none. It has display:block when I blur on some of li. So the problem goes deeper. I haven't any possibility to add event like onBlur. I should do now something like:</p>
  
  <pre><code>    Event.observe(window, 'load',
          function()  {
              $('li.cl1').observe('blur', MenuItemBlock);
      });
  
      function MenuItemBlock(event)
      {
          alert("!");
          var element = Event.element(event);
      }
  </code></pre>
  
  <p>But it doesn't work also. I don't get an alert.</p>