스크롤바 따라다니는 레이어

$(document).ready(function(){
 // sticky menu 설정
 var stickymenu = function(isInit){
  var marginLeft = 500;
  var layerLeft = document.body.clientWidth / 2 + marginLeft;
  var marginTop = 150;
  var currentTop = parseInt($("#stickymenu").css("top"));
  var animateTime = 500;

  if(isInit == true){
   currentTop = marginTop;
  }

  //alert(currentTop);
 
  $("#stickymenu").attr("style", "position:absolute; top:" + marginTop + "px; left:" + layerLeft + "px;");

  $(window).scroll(function(){
   var position = $(window).scrollTop();

   $("#stickymenu").stop().animate({"top":position + currentTop + "px"}, animateTime);
  });

 }

 stickymenu(true);
});

<div id="stickymenu">

    내용

</div>