function ajustar() {
  mh = document.getElementById('menu').offsetHeight
  ph = document.getElementById('ppal').offsetHeight + 8;
  if (document.getElementById('noticias')) {
    nh = document.getElementById('noticias').offsetHeight
  } else {
    nh = 0
  }
  th = Math.max(ph, mh, nh)
  if (th) {
    document.getElementById('menu').style.height = th + "px"
    document.getElementById('ppal').style.height = th + "px"
    if (document.getElementById('noticias')) {
      document.getElementById('noticias').style.height = th + "px"
    }
  }
}