var refreshinterval=20 
var starttime 
var nowtime 
var reloadseconds=0 
var secondssinceloaded=0 
function starttime() { 
   starttime=new Date() 
   starttime=starttime.getTime() 
   countdown() 
} 
function countdown() { 
   nowtime= new Date() 
   nowtime=nowtime.getTime() 
   secondssinceloaded=(nowtime-starttime)/1000 
   reloadseconds=Math.round(refreshinterval-secondssinceloaded) 
   if (refreshinterval>=secondssinceloaded) { 
      var timer=setTimeout("countdown()",1000) 
      //window.status="Page refreshing in "+reloadseconds+ " seconds" 
      //window.Title="Page refreshing in "+reloadseconds+ " seconds"
      swap_txt("refresh","Page refreshing in "+reloadseconds+ " seconds"); 
   } else { 
      clearTimeout(timer) 
      window.location.reload(true) 
   } 
} 
function swap_txt(tagid,txt) {	
   var old = document.getElementById(tagid).firstChild;
   var txt = document.createTextNode(txt);
   document.getElementById(tagid).replaceChild(txt, old);      
}
window.onload=starttime