function show_submenu2(a) {
    var element = document.getElementById('sub_menu_'+a);
    element.style.display = 'block';
}

function hide_submenu2(a) {
    var element = document.getElementById('sub_menu_'+a);
    element.style.display = 'none';
}

function show_portfolio(a) {
    var element = document.getElementById('sub_menu_'+a);
    
    var menu = document.getElementById('menu_'+a);
    var posx = menu.offsetLeft + menu.offsetWidth - 2;
    var posy = menu.offsetTop;
    
    element.removeAttribute('style');
    element.setAttribute('style' , 'display: block; position: absolute; top: ' + posy + 'px; left: ' + posx + 'px;');
}

function hide_portfolio(a) {
    var element = document.getElementById('sub_menu_'+a);
    element.style.display = 'none';
}