Untitled

<html>
<head>
    <title>Digitron</title>
    <script language="JavaScript">

        function izracunaj(operacija) {
            var broj1 = parseInt(document.racunaljka.br1.value);
            var broj2 = parseInt(document.racunaljka.br2.value);
            var rezultat = 0;

            if ((isNaN(broj1) == false) && (isNaN(broj2) == false)) {
                switch (operacija) {
                    case 1: rezultat = broj1 + broj2;
                        break;
                    case 2: rezultat = broj1 - broj2;
                        break;
                    case 3: rezultat = broj1 * broj2;
                        break;
                    case 4: rezultat = broj1 / broj2;
                        break;
                }
                document.racunaljka.rez.value = rezultat;
            } else {
                alert("Digitron radi samo sa brojevima");
            }
        }
    </script>
</head>
<body>
<h1 align='center'>D I G I T R O N</h1>
<table border='0' align='center'>
    <form name="racunaljka" action="" method="">
        <tr>
            <td>Unestite prvi broj:</td>
            <td><input type="text" name="br1" value="" /> </td>a
        </tr>
        <tr>
            <td>Unesite drugi broj: </td>
            <td><input type="text" name="br2" value="" /> </td>
        </tr>
        <tr>
            <td colspan='2' align='center'>
                <input type="button" name="saberi"
                       value=" + " onClick="izracunaj(1);" />
                <input type="button" name="oduzmi"
                       value=" - " onClick="izracunaj(2);" />
                <input type="button" name="pomnozi"
                       value=" * " onClick="izracunaj(3);" />
                <input type="button" name="podeli"
                       value=" / " onClick="izracunaj(4);" />
            </td>
        </tr>
        <tr>
            <td colspan='2' align='center'>
                Rezultat :
                <input type="text" name="rez"
                       value="" readonly="readonly"/>
            </td>
        </tr>
    </form>
</table>
</body>
</html>