var timeout = 500;
           var closetimer = 0;
           var menuitem = 0;

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

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

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

           function eopen() {
               //cancel close timer
               mcancelclosetime();

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

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

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

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

           document.onclick = mclose;