var saveLastMenuItem = 0;
var saveCloseElapsedTime = 0;
var standardTimer = 500;

function openAMenu(whichMenu) {
    cancelTimeToClose();

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

    saveLastMenuItem = document.getElementById(whichMenu);
    saveLastMenuItem.style.visibility = 'visible';

}

function closeAMenu() {
    if (saveLastMenuItem) saveLastMenuItem.style.visibility = 'hidden';
}

function closeTimer() {
    saveCloseElapsedTime = window.setTimeout(closeAMenu, standardTimer);
}

function cancelTimeToClose() {
    if (saveCloseElapsedTime) {
        window.clearTimeout(saveCloseElapsedTime);
        saveCloseElapsedTime = null;
    }
}
document.onclick = closeAMenu;