the summation is shown in all browser correctly . Now when i delete row the value of summation will be decrease but in firefox browser does not show it correctly. Suppose 10 + 10 + 10 = 30 if delete 2 row then sum shows 20 . But this will be 10. What's going wrong. 

```
<script>
    $(document).ready(function () {
        $("form").on('keyup', '.input_ttotal', function() {
            calculateSum();
        });

        $('#btnDel').click(function () {
            calculateSum();
        });

    });

    function calculateSum() {

        var sum = 0;

        $(".input_ttotal").each(function () {
            if (!isNaN(this.value) && this.value.length != 0) {
                sum += parseFloat(this.value);
            }
        });
        $("#sum").html(sum.toFixed(2));
    }
    </script>

```

Html is

```
<form action="" method="POST">
    <div class="yes">
        <div id="cost1" class="clonedCost" style="display: inline;">
            <table border="0">
                <tr>
                    <td>
                        <label class="total" for="total">Total 1</label>
                    </td>
                </tr>
                <tr>
                    <input class="input_ttotal" id="ttotal" type="text" name="ttotal[]" />
                    </td>
                </tr>
            </table>
        </div>
        <div id="addDelButtons_cost">
            <input type="button" id="btnAdd" value="+">
            <input type="button" id="btnDel" value="-">
        </div>
        <p>Sum is:<span id="sum">0</span>
        </p>
    </div>
</form>

```

jsfiddle link is <http://jsfiddle.net/ByLrz/1/>