function activeNav(id, position) {

    var navigationDiv = document.getElementById(id);
    navigationDiv.onmouseover = null;
    navigationDiv.onmouseout = null;

    if (position == null) {
        navigationDiv.style.background = 'url(images/nexttheme/navigation/bg_nav_active.png)';
    }
    else if (position == 'first') {
        navigationDiv.style.background = 'url(images/nexttheme/navigation/bg_nav_first_active.png)';
    }
    else if (position == 'last') {
        navigationDiv.style.background = 'url(images/nexttheme/navigation/bg_nav_last_active.png)';
    }

}