function alternate(id) {
    if (document.getElementsByTagName) {
        var table = document.getElementById(id);
        var rows = table.getElementsByTagName("tr");
        for (i = 0; i < rows.length; i++) {
            //manipulate rows
            if (i % 2 == 0) {
                rows[i].className = "d0";
            } else {
                rows[i].className = "d1";
            }
        }
    }
}