function trace(str){
  document.getElementById('trace').innerHTML=str;
}

var img=new Array();
var k=0;
var timeout=4000;

function logo_change()
{
  k++;
  document.getElementById(img[k-1]).style.display='none';
  if(k>=img.length)
  {
    k=0;
  }
  document.getElementById(img[k]).style.display='inline';
  setTimeout(logo_change,timeout);
}

function init_logo()
{
  var imgs=document.getElementById('left').getElementsByTagName('img');
  if(imgs.length>1)
  {
    for(i=0;i<imgs.length;i++)
      img[i]=imgs[i].id;
    setTimeout(logo_change,timeout);
  }
}

 if (window.attachEvent) window.attachEvent('onload', init_logo);
 if (window.addEventListener) window.addEventListener('load', init_logo,false);