ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false

function on(id) {
        if (ns4) document.layers[id].visibility = "show"
        else if (ie4) document.all[id].style.visibility = "visible"
}
function off(id) {
        if (ns4) document.layers[id].visibility = "hide"
        else if (ie4) document.all[id].style.visibility = "hidden"
}
function nonr(e) {
if (navigator.appName == 'Netscape' && (e.which == 3 || e.which == 2))return false;
else if (navigator.appName == 'Microsoft Internet Explorer' && (event.button == 2 || event.button == 3)) {
alert("ごめんね　");return false;
}
return true;
}
document.onmousedown=nonr;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
window.onmousedown=nonr;