[vwphillips]

window.onscroll = function (e) {
var basediv = document.getElementById('basediv').offsetTop;
var setdiv = document.getElementById('setdiv');
var top=getScroll()[1];
 if (top < basediv) {
 setdiv.style.top = "0px";
 }
 else {
 setdiv.style.top = top - basediv + "px");
 }
}

function getScroll(){
 if (window.innerHeight){
  return [window.pageXOffset,window.pageYOffset];
 }
 else if (document.documentElement.clientHeight){
  return [document.documentElement.scrollLeft,document.documentElement.scrollTop];
 }
 return [document.body.scrollLeft,document.body.scrollTop];
}