var GO = function(elemId) {
    return document.getElementById(elemId);
}

function menu2(mid, idx) {
    class_name = 'menu2_0' + idx;
    GO("m2_" + mid + "_" + idx).className = class_name + ' on';
    GO("c2_" + mid + "_" + idx).style.display = "";
    for (var i = 1; i < 10; i++) {
        class_name = 'menu2_0' + i;
        if (!GO("m2_" + mid + "_" + i)) continue;
        if (i != idx) {
            GO("m2_" + mid + "_" + i).className = class_name;
            GO("c2_" + mid + "_" + i).style.display = "none";
        }
    }
}