Kalkulator Sederhana (JavaScript & Form HTML)

<!-- Indonesian C0der Leak -->
<!-- Created By : Ilham Wicaksono :) -->

<html>
    <head>
        <title>Kalkulator Sederhana</title>
        <script type="text/javascript">
            function Kalkulator(check)
            {
                var bil1 = parseFloat(document.kalku.bil1.value);
                var bil2 = parseFloat(document.kalku.bil2.value);
                var hasil;
                if (check == 'jumlah') hasil = bil1+bil2;
                else if (check == 'kurang') hasil = bil1-bil2;
                else if (check == 'kali') hasil = bil1*bil2;
                else if (check == 'bagi') hasil = bil1/bil2;
                else hasil = 'Tidak Ada Operasi';
                document.kalku.result.value=hasil;
            }
        </script>
    </head>
    <body>
        <form name="kalku" onsubmit="return false">
        <h2>Kalkulator Sederhana</h2>
        <table>
            <tr>
                <td>Input Bilangan 1</td>
                <td>:</td>
                <td><input type="text" name="bil1"/></td>
            </tr>
            <tr>
                <td>Input Bilangan 2</td>
                <td>:</td>
                <td><input type="text" name="bil2"/></td>
            </tr>
            <tr>
                <td>Hasil Operasi</td>
                <td>:</td>
                <td><input type="text" name="result"/></td>
            </tr>
            <tr>
                <td><button onclick="Kalkulator('jumlah')">+</button><button onclick="Kalkulator('kurang')">-</button><button onclick="Kalkulator('kali')">x</button><button onclick="Kalkulator('bagi')">/</button></td>
            </tr>
        </table>
        </form>
    </body>
</html>