startList = function() {

    if (document.all && document.getElementById) {

        navRoot = document.getElementById('nav');

        for (i=0; i<navRoot.childNodes.length; i++) {

            node = navRoot.childNodes[i];

            if (node.nodeName == 'LI') {

                node.onmouseover = function() {

                    this.className += ' over';

                }

                node.onmouseout = function() {

                    this.className = this.className.replace(" over", "");

                }

            }

        }

    }

}

addLoadEvent(function() {
    startList();
});