jQuery : slideDown() , slideUp() and stop()

I have a menu strip . I planned to :

1. slideDown() a submenu ( originally display: none DIV ) when I mouse over the menu strip
2. hide the submenu by slideUp when mouse out.

Here is the codes:

<div id="main_menu" onmouseover="$('#submenu').stop(true,false).slideDown();" onmouseout="$('#submenu').stop(true,false).slideUp();">Main Menu</div>
<div id="submenu" style="display: none">Some submenu contents here</div>

What I try to achieve is, when I mouseover submenu，the submenu holds and stop the mouse out ( the slideUp() animation. How can I achieve it ?

Note: given that the main_menu and sub_menu did not overlap.

UPDATE: here is the the jsFiddle

An easy way you can do is adding a parent dom, and binding the mouse event to it.

html

<div id="menu">
    <div id="main_menu">Main Menu</div>
    <div id="submenu" style="display: none">Some submenu contents here</div>
</div>

js

$('#menu').hover(function () {
    $('#submenu').stop(true, false).slideDown();
},

function () {
    $('#submenu').stop(true, false).slideUp();
});

here is jsfiddle demo. http://jsfiddle.net/vyDVd/

update

If you don't want to adding a parent dom, you can try putting submenu into main_menu as a child menu.

I update your jsfiddle demo here http://jsfiddle.net/9KfYr/2/

I add 2 css attributes to #submenu to keep UI unchange.

position:absolute;
top:30px;

And here, I suggest use .hover() provided by jQuery.