$(document).ready(function(){

$('.middlemenu ul li').hover(function(){  

   $(this).children('.submenus').css({
          'z-index':'100'     
          });
   if($(this).children('.submenus').is(':visible')) 
        $(this).children('.submenus').css({'display':'none'});
   else $(this).children('.submenus').css({'display':'block'});
   $(this).focus();
   
},
 function() {
   $(this).children('.submenus').css({'display':'none'});
 });

});