<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app">
        <input onchange="getText()" type="text" id="fromUser">
        <div id="inputText">Fra Bruker</div>
        <div id="reverseText">Reversert</div>
    </div>
    <script>
        var inputText;
        function getText() {
            inputText = document.getElementById('fromUser').value;
            document.getElementById('inputText').innerHTML = inputText;
            reverseText(inputText);
        }
        function reverseText(textToReverse) {
            document.getElementById('reverseText').innerHTML = ' ';
            for (i = textToReverse.length; i >= 0; i--) {
                document.getElementById('reverseText').innerHTML += textToReverse.charAt(i);
            }
        }

    </script>
</body>

</html>