title: google maps height 100% of div parent
body: <p>Is it possible make a google map height 100% of the parent div?
  I noticed that with the height 100%, the map is not visible, but if I add the height of the div with the map in pixel the map is correctly visualize.
  is there some tricks to achieve the map 100% of the parent div?
  this doesn't works</p>
  
  <pre><code>&lt;div class="block halfrect"&gt;
      &lt;div id="map" style="height:100%;"&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>this works</p>
  
  <pre><code>    &lt;div class="block halfrect"&gt;
          &lt;div id="map" style="height:590px;"&gt;&lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>any idea?</p>