var timeout	= 500;
var closeTimer	= 0;
var cascadeItem	= 0;

function MenuOpen(id)
{	
    MenuCancelCloseTime();
    if(cascadeItem) 
        cascadeItem.style.visibility = 'hidden';
    cascadeItem = document.getElementById(id);
    cascadeItem.style.visibility = 'visible';
}

function MenuClose()
{
    if(cascadeItem)
        cascadeItem.style.visibility = 'hidden';
}

function MenuCloseTime()
{
    closeTimer = window.setTimeout(MenuClose, timeout);
}

function MenuCancelCloseTime()
{
    if(closeTimer)
    {
        window.clearTimeout(closeTimer);
        closeTimer = null;
    }
}

document.onclick = MenuClose;