am = "Zakazane kopiowanie treści!"; 

bV = parseInt(navigator.appVersion) 
bNS = navigator.appName=="Netscape" 
bIE = navigator.appName=="Microsoft Internet Explorer" 

function nrc(e) { 
if (bNS && e.which > 1){ 
alert(am) 
return false 
} else if (bIE && (event.button >1)) { 
alert(am) 
return false; 
} 
} 

document.onmousedown = nrc; 
if (document.layers) window.captureEvents(Event.MOUSEDOWN); 
if (bNS && bV<5) window.onmousedown = nrc;