var startY = 0;
var sy;
function floatMenu()
{
  if(document.documentElement.scrollTop)
  {
    sy = document.documentElement.scrollTop;
  }
  else
  {
    sy = document.body.scrollTop;
  }
  var temp = sy + startY;
  var newY = temp.toString() + "px";
  var elem = document.getElementById("menufloat");
  elem.style.top = newY;
}
window.onscroll = floatMenu;