Event.observe(window, 'load',   fixBackground);
Event.observe(window, 'resize', fixBackground);

function fixBackground() {

  var ht = 0;

  dh = document.documentElement.clientHeight;
  wh = document.documentElement.scrollHeight;

  if ($('t3') != null)
  {

  	if (dh - wh == 0)
  	{
  		$('t3').style.position = 'absolute';
  		$('t3').style.bottom = '0';
  	}
  }
}