function HoverOverNav(imageId, num) {
    image = document.getElementById(imageId);
    if (image) {
        image.src = '_img/primary-nav-' + num + '-active.png';
    }
}

function HoverOffNav(imageId, num) {
    image = document.getElementById(imageId);
    if (image) {
        //alert('off');
        image.src = '_img/primary-nav-' + num + '.png';
    }
}