Untitled

<html>
<head>
  <style type="text/css">
  #graphline  {
  display:block;
  width:10px;
  height:200px;
  background-color:#000;
  }
  #graphline {
    -webkit-transition:all 500ms;
  }
  #graphline.full {width:500px;}
  #graphline.back {
    -webkit-transition:none;
  }
  </style>
</head>
<body>
  <button onclick="document.getElementById('graphline').className='full';">Animate!</button>
  <button onclick="document.getElementById('graphline').className='back';">Reset</button>
  <div id="graphline"></div>
</body>
</html>