function navigation_init() {
    if (!(nav = document.getElementById('navigation'))) {
        return;
    }
    for (var i = 0; i < nav.childNodes.length; i++) {
        nav.childNodes[i].onmouseover = function() {this.className = 'active';};
        nav.childNodes[i].onmouseout = function() {this.className = '';};
    }
}