title: Native javascript equivalent to jQuery.draggable()
body: <p>Is there a native javascript code equivalent to jQuery's draggable?
  I don't need all the features but</p>
  
  <ol>
  <li>being able to drag a modal window from a handle.</li>
  <li>on start and on end
  events as I need to make an overlay layer while dragging to prevent
  the mouse being upon the iframe inside the modal window.</li>
  <li>there will be only one draggable item on the document.</li>
  </ol>