function ShowHide(id1, id2) {
  if (id1 != '') expMenu(id1);
  if (id2 != '') expMenu(id2);
}

function expMenu(id) {
  var itm = null;
  if (document.getElementById) {
        itm = document.getElementById(id);
  } else if (document.all){
        itm = document.all[id];
  } else if (document.layers){
        itm = document.layers[id];
  }

  if (!itm) {
   // do nothing
  }
  else if (itm.style) {
        if (itm.style.display == "none") { itm.style.display = ""; }
        else { itm.style.display = "none"; }
  }
  else { itm.visibility = "show"; }
}