Untitled

<!DOCTYPE html>
<html lang="pl">
	<head>
		<title>szyfr cezara</title>
		<meta charset="utf-8" />
	</head>
	<body>
	<textarea id="message" rows="5" cols="40" ></textarea><br />
	<button id="encode">Szyfruj</button> <button id="decode">Odszyfruj</button><br />
	<textarea id="cipher" rows="5" cols="40"></textarea>


	<script>
		document.getElementById('encode').addEventListener('click',function(){
			var message = document.getElementById('message').value;
			var cipher = document.getElementById('cipher');
			cipher.value = ' ';
			for(var i=0; i < message.length; i++)
				cipher.value += String.fromCharCode(message.charCodeAt(i)+3)

					});
				document.getElementById('decode').addEventListener('click',function(){
			var cipher = document.getElementById('cipher').value;
			var message = document.getElementById('message');
			message.value = ' ';
			for(var i=0; i < cipher.length; i++)
				message.value += String.fromCharCode(cipher.charCodeAt(i)-3)


		});
	</script>
	</body>
</html>