function menuon(m)
{
    m.style.backgroundColor = "#000000";
    m.style.color = "#ffffff";
    //now change link text colour
    var n = m.id.substring(5);
    var l = document.getElementById(n + "_menu");
    l.style.color = "#ffffff";
}
function menuoff(m)
{
    m.style.backgroundColor = "#ffffff";
    m.style.color = "#000000";
    //now change link text colour
    var n = m.id.substring(5);
    var l = document.getElementById(n + "_menu");
    l.style.color = "#000000";
}