// JavaScript Document
function positionByObjY(obj_id,pos_parent_id,offset)
{
  var  obj=document.getElementById(obj_id);
  var  pos_parent=document.getElementById(pos_parent_id);
  var offs=AbsTop(pos_parent);
  obj.style.pixelTop=offs+offset
}
function AbsTop(obj)
{
  var _top=obj.offsetTop;
  while(obj.offsetParent)
  {
    obj=obj.offsetParent;
    _top+=obj.offsetTop;
  }
  return _top;
}