cssdropdown.startchrome("chromemenu");

function imageNavOn(refNav) {
    document.getElementById('nav0' + refNav).src = '/images/nav/nav0' + refNav + '_on.gif';
}

function imageNavOff(refNav) {
    document.getElementById('nav0' + refNav).src = '/images/nav/nav0' + refNav + '.gif';
}