title: CSS: background image does not fill when scrolling
body: <p>working on a very small site which loads in one go, so there is a div which holds all the background images, and on top of that (i.e. <strong>higher z-index</strong>) there is a content div which holds everything. I can switch backgrounds easily based on what content is selected.</p>
  
  <p>Unfortunately, I noticed if you launch in a small window so that scrollbars appear, <strong>if you scroll there is no background image</strong> in the 'revealed' portions of the page. :-(</p>
  
  <p>Page structure:</p>
  
  <pre><code>&lt;body&gt;
  &lt;div id="bg"&gt;
      &lt;div class="bgone"&gt;&lt;/div&gt;
      &lt;div class="bgtwo"&gt;&lt;/div&gt;
  &lt;/div&gt;
  
  &lt;div id="container"&gt;
  &lt;!-- content panels here --&gt;
  &lt;/div&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>css:</p>
  
  <pre><code>#bg
  {
      margin: 0px;
      position: absolute;
      top: 0px;
      left: 0px;
      width:100%;
      height: 1024px;
      z-index:1;
  }
  .bgone
  {
      margin: 0px;
      position: absolute;
      width:100%;
      height: 1024px;
      background-image:url(../images/one.jpg);
      background-position:top;
      background-repeat:repeat-x;
      z-index:2;
  }
  .bgtwo
  {
      margin: 0px;
      position: absolute;
      width:100%;
      height: 1024px;
      background-image:url(../images/two.jpg);
      background-position:top;
      background-repeat:repeat-x;
      z-index:3;
  }
  #container
  {
      position:relative;
      width:900px;
      padding:0px;
      margin:0px auto;
      height:600px;
      z-index:10;
  }
  </code></pre>