function hideDropdown() {

    var li = document.getElementsByTagName('li');

    for (var i= 0; i <li.length; i++) {
        if (li[i].className.indexOf("secondLevel") > 1) {
            li[i].style.display = "none";
        }
    }
}

function showDropdown(what) {
    var li = document.getElementsByTagName('li');

    for (var i= 0; i <li.length; i++) {
        if (li[i].className.indexOf(what) !== -1) {
            li[i].style.display = "block";
        }
    }    

}