[walik]

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
<style>
#bar {background-color: black;width:5px;height:20px;}
</style>
<div id="bar"></div>
<script>
$(function() {
   setInterval(function() {
      h = Math.random()*100;
      $('#bar').animate({height: h}, 300);
   }, 300)
});
</script>