객체 위치 구하기~

function getPos(obj){
 var xy = { x: 0, y: 0 };
 while (obj)
 {
  xy.x += obj.offsetLeft; xy.y += obj.offsetTop;
  if(obj.tagName != "BODY") {
   xy.x -= obj.scrollLeft; xy.y -= obj.scrollTop;
  }
  obj = obj.offsetParent;
 }
 return xy;
}

var pos = getPos(document.getElementById("htmls79"));
pos.x; pos.y;