title: How to create the effect of stacking and religning divs in javascript and html?
body: <p>Assume I have a single div with two buttons to add box and remove box:</p>
  
  <pre><code>&lt;div id="container" height=500 width=300&gt;
  &lt;/div&gt;
  &lt;button&gt;Add&lt;/button&gt;
  &lt;button&gt;Remove&lt;/button&gt;
  </code></pre>
  
  <p>Clicking on Add would "add" a div to the container of width "200" and height= "200" with the letter "X". Clicking on "add" a second time would add a box of the same size right above it.</p>
  
  <p>Clicking on any of the "X" on a div would cause the div to disappear and the other divs below it would slide up to fill its space.</p>
  
  <p>Clicking on remove would remove the top box and cause any other divs below to slide up to take its space.</p>
  
  <p>How to accomplish this effect in Javascript?</p>