var x = (screen.width/2)-210;
var y = 200;
function setVisible(obj)
{
  obj = document.getElementById(obj);
  obj.style.visibility = (obj.style.visibility == 'visible') ? 'hidden' : 'visible';
}
function placeIt(obj)
{
  obj = document.getElementById(obj);
  if (document.documentElement)
  {
    theLeft = document.documentElement.scrollLeft;
    theTop = document.documentElement.scrollTop;
  }
  else if (document.body)
  {
    theLeft = document.body.scrollLeft;
    theTop = document.body.scrollTop;
  }
  theLeft += x;
  theTop += y;
  obj.style.left = theLeft + 'px' ;
  obj.style.top = theTop + 'px' ;
  setTimeout("placeIt('popupbox')",500);
}
window.document.onscroll = setTimeout("placeIt('popupbox')",500);