if (document.layers){
    window.captureEvents(Event.MOUSEDOWN | Event.MOUSEUP)
    window.onmousedown=rightclick;
    window.onmouseup=rightclick;

    function rightclick(e) {
    if (e.which == 3) {
        return false;
        }
    else {
        return true;
        }
    }
}

if (document.all){
    function click() {
        if (event.button==2)
        {
            alert('Copyright ©')
        }

        if (event.button==3)
        {
            alert('Copyright ©')
        }
    }
    document.onmousedown=click;
}