var msg = "Copyright on code and gaphics" ;

if ( navigator.appName == "Netscape")
          document.captureEvents(Event.MOUSEDOWN);

 function copyright(e){
        if( navigator.appName =="Netscape" &&
          (e.which == 2 || e.which == 3 )){
          alert(msg); return false;}

        if( navigator.appName =="Microsoft Internet Explorer"
          && (event.button == 2 || event.button == 3)){
          alert(msg);return false;}
}
window.onmousedown == copyright;
document.onmousedown = copyright;