var clickmessage="copyright: associazione NOI E..." 

function destro1(e) 
{
            if (navigator.appName == 'Netscape' && (e.which > 1))
            {
                        //alert(clickmessage);
                        return false;
            }
            else if (navigator.appName == 'Microsoft Internet Explorer' && (event.button == 2 || event.button == 3))
            {
                        //alert(clickmessage);
                        return false;
            }
            else
                return true;
}

 

function destro2()
{
            return false;
}

 

document.onmousedown=destro1;

document.onmouseup=destro1;

document.oncontextmenu = destro2;

if (document.layers) window.captureEvents(Event.MOUSEDOWN);
            window.onmousedown=destro1;

for (var i=0; i<document.images.length; i++)
  document.images[i].onmousedown=destro1;

for (var i=0; i<document.links.length; i++)
   document.links[i].onmousedown=destro1;