var timeout         = 250;
   var closetimer      = 0;
   var ddmenu          = 0;
   var pcmenu          = 0;

   function mopen(id)
   {   
      mcancelclosetime();
      mclose();
      ddmenu = document.getElementById(id);
      ddmenu.style.visibility = 'visible';
   }

   function mclose()
   {
      if(ddmenu) ddmenu.style.visibility = 'hidden';
   }

   function mclosetime()
   {
      closetimer = window.setTimeout(mclose, timeout);
   }

   function mcancelclosetime()
   {
      if(closetimer)
      {
         window.clearTimeout(closetimer);
         closetimer = null;
      }
   }
   document.onclick = mclose;