var theWarning="WARNING!\n This content is copyrighted.\n You may not copy it.";

function forIE4(){
	if (event.button==2){
		alert(theWarning);
		return false;
	}
}
function forNS(e){
	if (document.getElementById&&!document.all||document.layers){
		if (e.which==2||e.which==3){
			alert(theWarning);
			return false;
		}
	}
}
if (document.layers){
	document.captureEvents(Event.MOUSEDOWN);
	document.onmousedown=forNS;
}
else if (document.all&&!document.getElementById){
	document.onmousedown=forIE4;
}
document.oncontextmenu=new Function("alert(theWarning);return false")