function f_mmm () {
  if (document.body.offsetWidth < 1000) {
    document.getElementById("menu").style.left = "0";
    document.getElementById("menu").style.margin = "0";
  } else {
    document.getElementById("menu").style.left = "50%";
    document.getElementById("menu").style.margin = "0 0 0 -504px";
  }
  if (document.body.offsetHeight < 768) {
    var h = document.body.offsetHeight - 208;
    document.getElementById("menu").style.height = h + "px";
  } else {
    document.getElementById("menu").style.height = "560px";
  }
}