function stopmouse(e) { 
if (navigator.appName == 'Netscape' && (e.which == 3 || e.which == 2)) 
return false; 
else if 
(navigator.appName == 'Microsoft Internet Explorer' && (event.button == 2 || event.button == 3)) { 
alert("*** No Permission ***");
return false; 
}
return true; 
} 
document.onmousedown=stopmouse; 
if (document.layers) 
window.captureEvents(Event.MOUSEDOWN); 
window.onmousedown=stopmouse;