function non(clic) {
       var msg=" Oups !!  That's mine !! ";
       if (navigator.appName == 'Netscape' && clic.which==3) {alert(msg);
       return false;}
       else
       if (navigator.appName == 'Microsoft Internet Explorer' && event.button==2) {alert(msg);
       return false;}
       return true;}document.onmousedown = non;