JS实现表单输入Enter键转换焦点框

<form>
    <input type="text" onkeypress="return handleEnter(this, event)"><br>
    <input type="text" onkeypress="return handleEnter(this, event)"><br>
    <textarea onkeypress="return handleEnter(this, event)">回车切换焦点</textarea>
</form>
    <script type="text/javascript">
    function handleEnter (field, event) {
        var keyCode = event.keyCode ? event.keyCode : event.which ?
        event.which : event.charCode;
        if (keyCode == 13) {
            var i;
            for (i = 0; i < field.form.elements.length; i++)
                if (field == field.form.elements[i])
                break;
                i = (i + 1) % field.form.elements.length;
                field.form.elements[i].focus();
                return false;
        }
        else
        return true;
    }
</script>

$(function () {
        $('input:text:first').focus();
        var $inp = $('input:text');
        $inp.bind('keydown', function (e) {
            var key = e.which;
            if (key == 13) {
                e.preventDefault();
                var nxtIdx = $inp.index(this) + 1;
                $(":input:text:eq(" + nxtIdx + ")").focus();
            }
        });
    });