title: Overlapping one Div onto Another
body: <p>I'm trying to get a very specific look for my navigation. I want the background to be a solid image and I want the links to be separated text images that float above it to make it look like a piece. I've got it aligned perfectly, the issue is that I can't get the links to appear above the background. The code is below:</p>
  
  <pre><code>&lt;div id=Navigation&gt;
      &lt;div id="NavBar"&gt;
          &lt;img src="Site Images/Navigation/Nav_BG.png"/&gt;
      &lt;/div&gt;&lt;!--Nav Bar --&gt;
      &lt;div id="NavLinks"&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
          &lt;a href="x"&gt;&lt;img src="" /&gt;&lt;a&gt;
      &lt;/div&gt;&lt;!-- End of Navlinks --&gt;
  &lt;/div&gt;&lt;!-- End of Navigation Div --&gt;
  </code></pre>
  
  <p>The CSS is </p>
  
  <pre><code>#Navigation {
      height: 810px;
      width: 350px;
      float: left;
  }
  
  #NavBar {
      position: absolute;
      z: 2; /* What is `z`? */
  }
  
  #NavLinks{
      float: none;
      z: 1; /* What is `z`? */
  }
  </code></pre>
  
  <p>I tried the <code>z</code> attribute but it's not working. I know that something is wrong. The <code>div id="Navigation"</code> must float left, or the <code>div id="content"</code> (not added here) won't be next to it.</p>