var d = document;

function menu(objId){
  var obj = d.getElementById(objId);
  var a = obj.getElementsByTagName('A');

  for(x=0, y=a.length; x<y; x++){
    a[x].onmouseover  = function(){ mouseinout('in', this); }
    a[x].onmouseout   = function(){ mouseinout('out', this); }
  }
}

function mouseinout(action, obj){
  if(action == 'in' && obj.className != 'act'){
    var l = d.createElement('SPAN');
    l.className = 'l';
    l.innerHTML = '[';

    var r = d.createElement('SPAN');
    r.className = 'r';
    r.innerHTML = ']';

    obj.appendChild(l);
    obj.appendChild(r);
  }else if(action == 'out' && obj.className != 'act'){
    var span = obj.getElementsByTagName('SPAN');

    for(x=0, y=span.length; x<y; x++){
      obj.removeChild(span[0]);
    }
  }
}

window.onload = function(){ menu('menu'); }