var slideTime = 1000, topMargin;

window.onload = function()
{
  topMargin = 0;
  winOnResize(); // set initial position
  xAddEventListener(window, 'resize', winOnResize, false);
  xAddEventListener(window, 'scroll', winOnScroll, false);
  return;
}

function winOnResize()
{
  xMoveTo('floater', 0, topMargin);
  xShow('floater');
  winOnScroll(); // initial slide
}

function winOnScroll()
{
  if (xClientHeight() > 450)
  {
    xSlideTo('floater', xLeft('floater'), xScrollTop() + topMargin, slideTime);
  }
}