var message = "function disabled"; 
function rtclickcheck(keyp){ 
if (navigator.appName == "Netscape" && keyp.which == 3) {alert(message); return false; } 
if (navigator.appVersion.indexOf("MSIE") != -1 && event.button == 2) { 	alert(message); 	return false; } } 
document.onmousedown = rtclickcheck;