// A function for determining how far horizontally the browser is scrolled
  function scrollX() {
      // A shortcut, in case we’re using Internet Explorer 6 in Strict Mode
      var de = document.documentElement;
  
      // If the pageXOffset of the browser is available, use that
      return self.pageXOffset ||
  
          // Otherwise, try to get the scroll left off of the root node
          ( de && de.scrollLeft ) ||
  
          // Finally, try to get the scroll left off of the body element
          document.body.scrollLeft;
  }
  
  // A function for determining how far vertically the browser is scrolled
  function scrollY() {
      // A shortcut, in case we’re using Internet Explorer 6 in Strict Mode
      var de = document.documentElement;
  
      // If the pageYOffset of the browser is available, use that
      return self.pageYOffset ||
  
          // Otherwise, try to get the scroll top off of the root node
          ( de && de.scrollTop ) ||
  
          // Finally, try to get the scroll top off of the body element
          document.body.scrollTop;
  }