function hide_all_menus() {
    for (menu in menus) {
        if (document.getElementById(menu)) {
           document.getElementById(menu).style.display='none';
           document.images[menus[menu].image_name].src= document.images[menus[menu].image_name].inactive_src;
           }
    }
}

function show_menu(menu_id) {
        if (menus[menu_id].timeout != null) {
            clearTimeout(menus[menu_id].timeout);
            menus[menu_id].timeout = null;
        }
        if (menus[menu_id].visible == false) {
//            hide_all_menus();
            document.getElementById(menu_id).style.display='inline';
            menus[menu_id].visible=true;
        }
}
function hide_menu(menu_id) {
        if (menus[menu_id].timeout == null) {
            menus[menu_id].timeout = setTimeout("document.getElementById('" + menu_id + "').style.display='none';menus['" + menu_id + "'].timeout=null;menus['" + menu_id + "'].visible=false;", 50);
        }
}