kalkulator

<?php

/*
INDEX.PHP

script kalkulator denga 1 input text
*/

$ask = null;
$return = null;

if (isset($_GET['ask'])) {
    $ask = $_GET['ask'];
}

if (isset($_GET['return'])) {
    $return = $_GET['return'];
}


?>
<html>
<head>
    <title></title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
</head>
<body>
    <form method="get" action="act.php">
        <input type="text" name="ask" value="<?=$ask?>" placeholder="type here">
        <input type="submit" name="proses" value="=">
        <input type="text" disabled="true" name="return" value="<?=$return?>" placeholder="no return yet">

    </form>


</body>
</html>

<script type="text/javascript">
$('input').bind('keypress', function (event) {
    var regex = new RegExp("^[0-9+*/().\-]+$");
    var key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
    if (!regex.test(key)) {
       event.preventDefault();
       return false;
    }
});
</script>