var timeout = 200; var closetimer = 0; var currItem = 0;
function menu_open(){
    menu_canceltimer();
    menu_close();
    currItem = $(this).find('ul').css('visibility', 'visible');
}
function menu_close(){
    if(currItem) currItem.css('visibility', 'hidden');
}
function menu_timer(){
    closetimer = window.setTimeout(menu_close, timeout);
}
function menu_canceltimer(){
    if(closetimer){
        window.clearTimeout(closetimer);
        closetimer = null;
    }
}
$(document).ready(function() {
    $('#menu_top > li').bind('mouseover', menu_open)
    $('#menu_top > li').bind('mouseout', menu_timer)
});
document.onclick = menu_close();