// Code thanks to JavaScript Array @ http://javascript-array.com/scripts/simple_drop_down_menu/
var timeout	= 500;
var closetimer	= 0;
var ddmenuitem	= 0;

// open hidden layer
function mopen(id)
{	
   // cancel close timer
   mcancelclosetime();

   // close old layer
   if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';

   // get new layer and show it
   ddmenuitem = document.getElementById(id);
   ddmenuitem.style.visibility = 'visible';
   ddmenuitem.style.display = '';

}
// close showed layer
function mclose()
{
   if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}

// go close timer
function mclosetime()
{
   closetimer = window.setTimeout(mclose, timeout);
}

// cancel close timer
function mcancelclosetime()
{
   if(closetimer)
   {
      window.clearTimeout(closetimer);
      closetimer = null;
   }
}

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