BHighlight pageup = h.get(H_PAGEUP);
BHighlight pagedown = h.get(H_PAGEDOWN);
if (pageup != null && pagedown != null) {
pageup.setVisible((top > 0) ? H_VIS_TRUE : H_VIS_FALSE);
pagedown.setVisible((top + nVisibleRows < rows.size()) ? H_VIS_TRUE : H_VIS_FALSE);
h.refresh(anim);
}
//
// 6. refresh row highlights if we still have focus
//