function hover(link) {
    var image = document.getElementById(link);
    image.src = "images/m_" + link + "_over.gif";
}
function unhover(link) {
    var image = document.getElementById(link);
    image.src = "images/m_" + link + ".gif";
}

function home_on() {
    var image = document.getElementById('homelink');
    image.src = "/images/t_logo_150_c.jpg";
}
function home_off() {
    var image = document.getElementById('homelink');
    image.src = "/images/t_logo_150_bw.jpg";
}