Help with javascript?

1

I have this code I found that uses a setInterval to rotate content. But I want to modify it to rotate the content when the web page is reloaded. Can someone help me with this?


<script type="text/javascript">
 
  var curcontentindex=0
  var messages=new Array()
 
  function getElementByClass(classname){
  var inc=0
  var alltags=document.all? document.all : document.getElementsByTagName("*")
  for (i=0; i<alltags.length; i++){
  if (alltags*.className==classname)
  messages[inc++]=alltags*
  }
  }
 
  function rotatecontent(){
  //get current message index (to show it):
  curcontentindex=(curcontentindex<messages.length-1)? curcontentindex+1 : 0
  //get previous message index (to hide it):
  prevcontentindex=(curcontentindex==0)? messages.length-1 : curcontentindex-1
  messages[prevcontentindex].style.display="none" //hide previous message
  messages[curcontentindex].style.display="block" //show current message
  }
 
 
 window.onload=function(){
   if (document.all || document.getElementById){
    getElementByClass("dyncontent")
    //need this to work on reload of web page
    setInterval("rotatecontent()", 2000)
   }
  }  
 
 
</script>
 
//my html code looks like this
 
<div class="employee_container">
      <div id="group1" class="dyncontent" style="display: block"></div>
      <div id="group2" class="dyncontent"></div>
      <div id="group3" class="dyncontent"></div>
</div>