var scrollActive = false, scrollStop = true, scrollIncrement=2, scrollInterval=20;
xAddEventListener(window, 'load',
  function () {
    var up = xGetElementById('upBtn');
    var dn = xGetElementById('dnBtn');
    var sc = xGetElementById('vScroller1');
  
    up.onmouseover = onScrollUpStart;
    up.onmouseout = onScrollStop;
    xMoveTo(up, xPageX(sc) + xWidth(sc), xPageY(sc));
   
    dn.onmouseover = onScrollDnStart;
    dn.onmouseout = onScrollStop;
    xMoveTo(dn, xPageX(sc) + xWidth(sc), xPageY(sc) + xHeight(sc) - xHeight(dn));
  }, false
);