var leftMenu_activeElement = null;
var leftMenu_activeMenuItem = null;
var leftMenu_activeSubMenuItem = null;

MENU_ITEM_LAST_ITEM = "menu_item last_item";
MENU_ITEM_LAST_ITEM_ACTIVE = "menu_item last_item active";
MENU_ITEM = "menu_item";
MENU_ITEM_ACTIVE = "menu_item active";
DISPLAY = "";
HIDE = "none";

function swith_menu(menu_element, submenu_element) {
    var subMenuItem = document.getElementById(submenu_element);
    var menuItem = document.getElementById(menu_element);

    switch (menuItem.className) {
        case MENU_ITEM_LAST_ITEM:
            setMenuItemStyleClass(menuItem, MENU_ITEM_LAST_ITEM_ACTIVE);
            setSubMenuItemStyle(subMenuItem, DISPLAY);
            break;
        case MENU_ITEM:
            setMenuItemStyleClass(menuItem, MENU_ITEM_ACTIVE);
            setSubMenuItemStyle(subMenuItem, DISPLAY);
            break;
        case MENU_ITEM_LAST_ITEM_ACTIVE:
            setMenuItemStyleClass(menuItem, MENU_ITEM_LAST_ITEM);
            setSubMenuItemStyle(subMenuItem, HIDE);
            break;
        case MENU_ITEM_ACTIVE:
            setMenuItemStyleClass(menuItem, MENU_ITEM);
            setSubMenuItemStyle(subMenuItem, HIDE);
            break;
        default:
    }

    if (leftMenu_activeMenuItem != null && leftMenu_activeMenuItem != menuItem) {
        switch (leftMenu_activeMenuItem.className) {
            case MENU_ITEM_LAST_ITEM_ACTIVE:
                setMenuItemStyleClass(leftMenu_activeMenuItem, MENU_ITEM_LAST_ITEM);
                setSubMenuItemStyle(leftMenu_activeSubMenuItem, HIDE);
                break;
            case MENU_ITEM_ACTIVE:
                setMenuItemStyleClass(leftMenu_activeMenuItem, MENU_ITEM);
                setSubMenuItemStyle(leftMenu_activeSubMenuItem, HIDE);
                break;
            default:
        }
    }

    leftMenu_activeSubMenuItem = subMenuItem;
    leftMenu_activeMenuItem = menuItem;
}

function setSubMenuItemStyle(element, value) {
    if (element != null)
        element.style.display = value;
}

function setMenuItemStyleClass(element, value) {
    if (element != null)
        element.className = value;
}

function swith_sub_menu(element) {
    element.className = "active";
    if (leftMenu_activeElement != null) {
        leftMenu_activeElement.className = "";
        //clean previous active element
    }
    leftMenu_activeElement = element;
    return false;

}