var timeout    = 500;
var closetimer = 0;
var ddmenuitem = 0;

function jsddm_open() {  
    jsddm_canceltimer();
    jsddm_close();
    ddmenuitem = $(this).find('ul').css('visibility', 'visible');
}
function jsddm_close() {  
    if(ddmenuitem) ddmenuitem.css('visibility', 'hidden');
}
function jsddm_timer() {  
    closetimer = window.setTimeout(jsddm_close, timeout);
}
function jsddm_canceltimer(){  
    if(closetimer) {  
        window.clearTimeout(closetimer);
        closetimer = null;
    }
}
$(document).ready(
    function() {  
        $('#jsddm > li').bind('mouseover', jsddm_open)
        $('#jsddm > li').bind('mouseout',  jsddm_timer)
    }
);
document.onclick = jsddm_close;