Untitled

<!DOCTYPE html>
<html lang="pl">
<head>
<meta charset="UTF-8">
<script type="text/javascript">
var pole;
var r2;
function polekola(){
var promien2 = document.forms['promien'].promien.value;
r2 = promien2*promien2;
pole = 3.141592653589793238462643383279502884197169*r2;
pole = Math.round(pole * 100) / 100;
document.write("Pole wynosi: " + pole);
return false;
}
function obwkola(){
var promien3 = document.forms['promien'].promien.value;
obw = 2*3.141592653589793238462643383279502884197169*promien3;
obw = Math.round(obw * 100) / 100;
document.write("Obwod wynosi: " + obw);
return false;
}
</script>
</head>
	<body>
	<form id="promien"><div>
	Podaj promien: <input type="text" name="promien"><br>
	<button onclick="polekola()">Oblicz pole</button>
	<button onclick="obwkola()">Oblicz obwód</button>
	</div></form>
	<br><div id="wynik"></div>
	</body>
	</html>