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

function mainmenu_open() {
    mainmenu_canceltimer();
    mainmenu_close();
    ddmenuitem = $(this).find('ul').eq(0).css('visibility', 'visible');
}

function mainmenu_close()
{ if (ddmenuitem) ddmenuitem.css('visibility', 'hidden'); }

function mainmenu_timer()
{ closetimer = window.setTimeout(mainmenu_close, timeout); }

function mainmenu_canceltimer() {
    if (closetimer) {
        window.clearTimeout(closetimer);
        closetimer = null;
    }
}

$(document).ready(function() {
    $('#mainmenu > li').bind('mouseover', mainmenu_open);
    $('#mainmenu > li').bind('mouseout', mainmenu_timer);
});

document.onclick = mainmenu_close;