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

function mopen(id)
{
        mcancelclosetime();

        if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';

        ddmenuitem = document.getElementById(id);
        ddmenuitem.style.visibility = 'visible';

}
function mclose()
{
        if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}

function mclosetime()
{
        closetimer = window.setTimeout(mclose, timeout);
}

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

document.onclick = mclose;