title: Overflow auto and position absolute issue
body: <p>I have "container" with overflow: auto. Inside this die i have "child" div with position: relative. Inside a child div I have a "banner" div with position: absolute. I want to show the banner at top right corner of child.But i m unable to see the banner.</p>
  
  <p>If I comment the overflow:auto statement of the  "container" div , then I am able to see.
  But I the container div to have overflow to get a scroll if content increases. Please see the following code.</p>
  
  <p>Html</p>
  
  <pre><code>&lt;div class="container"&gt;
      &lt;div class="child"&gt;
          &lt;div class="banner"&gt;
              Banner
          &lt;/div&gt;        
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Css</p>
  
  <pre><code>.container{
      max-height: 200px;
      overflow: auto;
      border: 2px solid blue;
      margin-top: 50px;
  }
  .child{
      position: relative;
      width: 200px;
      height: 50px;
      border: #000;
      background-color: green;
  }
  .banner{
      position: absolute;
      top: -20px;
      left:10px;
      height: 20px;
      width: 150px;
      border: 1px solid red;
      background-color: #ccc;
      color: #000;
      z-index: 400;
  }
  </code></pre>
  
  <p>Please refer the jsfiddle
  <a href="http://jsfiddle.net/anu1718/XDLm5/" rel="nofollow">http://jsfiddle.net/anu1718/XDLm5/</a></p>