Delay close toggle in jquery drop down menu

Question

I have a menu that slides out when an li is hovered. The problem is that when i hover the next li, the initial li that is open is still trying to slide up when the new li starts sliding out. There is an overlap. Is there a way to delay the next li sliding out till the previous open li has finished sliding up. cheers

<div class="mainmenu">
    <ul class="dropDownMenu ">
      <li><a href="#">Home</a></li>
      <li><a href="#">Books</a>
        <ul class="sub">
          <div class="boxwrapper">

$(this).find(".mainmenu .sub").hide();
$(".mainmenu ul li").hover(
function() {$(this).find(".sub").slideToggle(1000)})

Answer 1

Like this:

$('.mainmenu ul li').hover(function(){
  $('.mainmenu ul.sub').slideUp(1000, function(){
    $(this).slideDown(1000);
  });
});