var step_ratio = 0.1;
objs = new Array();
objs_x = new Array();
objs_y = new Array();
function addfollowmark(name, x, y) {
  i = objs.length;
  objs[i] = document.getElementById(name);
  objs_x[i] = x;
  objs_y[i] = y;
}
function followmark() {
  for(var i=0; i<objs.length; i++) {
    var fm = objs[i];
    var fm_x = typeof(objs_x[i]) == 'string' ? eval(objs_x[i]) : objs_x[i];
    var fm_y = typeof(objs_y[i]) == 'string' ? eval(objs_y[i]) : objs_y[i];
    if (fm.offsetLeft != document.body.scrollLeft + fm_x) {
      var dx = (document.body.scrollLeft + fm_x - fm.offsetLeft) * step_ratio;
      dx = (dx > 0 ? 1 : -1) * Math.ceil(Math.abs(dx));
      fm.style.left = fm.offsetLeft + dx;
    }
 var diffY;
 if (document.documentElement && document.documentElement.scrollTop)
 diffY = document.documentElement.scrollTop;
else if (document.body)
 diffY = document.body.scrollTop;
 
    if (fm.offsetTop != diffY  + fm_y) {
      var dy = (diffY  + fm_y - fm.offsetTop) * step_ratio;
      dy = (dy > 0 ? 1 : -1) * Math.ceil(Math.abs(dy));
      fm.style.top = fm.offsetTop + dy;
    }
    fm.style.display = '';
  }
}
//addfollowmark("ad_dl01", 5, 180);//
addfollowmark("ad_dl02", "document.body.clientWidth-128", 168);
setInterval('followmark()',20);