var active;
var timer;

function killActive(){
 if(active!=null){
  active.style.display='none';
  active=null;
 };
};

function showMenu(obj){
 killActive();
 tM=document.getElementById('M'+obj.id);
if(tM!=null){
 tM.style.left = obj.offsetLeft;
 tM.style.top = obj.offsetTop+obj.offsetHeight;
 overMenu(tM);
 active=tM;
 timer=setTimeout(function(){killActive();},1000);
 };
 };

function overMenu(obj){
if(timer)clearTimeout(timer);
obj.style.display='block';
};

function outMenu(){
timer=setTimeout(function(){killActive();},1000);
};