function roll(n) {
var ns="lay"+n;

if (navigator.appName=="Netscape") {
document.layers[ns].visibility = 'visible'
} else {
document.all[ns].style.visibility = 'visible'
}
}
function rolloff(n) {
var ns="lay"+n;
if (navigator.appName=="Netscape") {
document.layers[ns].visibility = 'hidden'
} else {
document.all[ns].style.visibility = 'hidden'
}
}