function div_ref_style (id) {
    if      (document.layers)         return document.layers[id];
    else if (document.all)            return document.all[id].style;
    else if (document.getElementById) return document.getElementById(id).style;
    else                              return null;
  }

  function help(id,stat) {
    div_ref_style(id).display =  stat? "" : "none";
  }