javascript实现字符串反转

<html>

<head>
<script language="javascript">
    function reverse()
    {
        var str=document.getElementById("input").value;
        var a=str.split('');
        var result=new Array();
        while(a.length)
        {
            result.push(a.pop());
        }
        document.getElementById("result").innerHTML=result.join('');
    }
</script>

<title>javascript</title>

</head>

<body>
    <table>
    <tr>
    <td><input type="textfield" id="input"/>=></td>
    <td><div id="result"></div></td>
    </tr>
    </table>
    <input type="button" value="reverse" onclick="reverse()"/>
</body>

</html>