function opensubmenu(id){
        closesubmenu('1');
        closesubmenu('2');
        closesubmenu('3');
        closesubmenu('4');
        closesubmenu('5');
        closesubmenu('6');
        var mysub = document.getElementById(id)
     mysub.style.visibility='visible';
}

function closesubmenu(id){
        var mysub = document.getElementById(id)
        mysub.style.visibility='hidden';
}