var leftMenuCloseTimer ;

$(function(){
  $("#left-menu li")
    .mouseenter(function(){
      var li = $(this);
      var sub = li.find("> .submenu");
      var brothers = li.parent().find(">li");
      var index = brothers.index(li);
      
      if(sub.size() == 0)
        return;
        
      brothers.find("> .submenu:visible").hide();
      clearTimeout(leftMenuCloseTimer);
      sub.show();
    })
    .mouseleave(function(){
      var li = $(this);
      var sub = li.find("> .submenu:visible");

      if(sub.size() == 0)
        return;
        
      leftMenuCloseTimer = setTimeout(function(){
        sub.hide();
      }, 100);
    });
});