var timeout = 500;
var cltimer = 0;
var pdmi    = 0;

// open menu
function mopen(id) {
   wstopTimeout();
   if(pdmi) pdmi.style.visibility = 'hidden';
   pdmi = document.getElementById(id);
   pdmi.style.visibility = 'visible';
}

// close menu
function mclose() {
   if(pdmi) pdmi.style.visibility = 'hidden';
}

function wsetTimeout() {
   cltimer = window.setTimeout(mclose, timeout);
}

function wstopTimeout() {
   if(cltimer) {
      window.clearTimeout(cltimer);
      cltimer = null;
   }}

// close layer when click-out
document.onclick = mclose;