计算自动更新

Question

TDR金额的字段＆＃34; 服务税（12.36％）：＆＃34;没有在表格中工作。

这应该自动从TDR金额计算ST金额（12.36％）并显示它，然后将其添加到总计最后

http://jsfiddle.net/813Lgvvt/

HTML

<form id="calculator" method="post">
<table class="tbl_insert">
    <tr>
        <th>
            <label for="amount">Amount:</label>
        </th>
        <td>
            <input type="text" name="amount" id="amount" value="" class="field" />
        </td>
    </tr>
    <tr>
        <th>
            <label for="tax">Card Type :</label>
        </th>
        <td>
            <select name="tax" id="tax" class="select">
                <option value="2.1">VISA</option>
                <option value="2.1">MasterCard</option>
                <option value="2.1">ICICI Bank</option>
                <option value="2.1">Diners Club Card</option>
                <option value="3.6">Amex Card</option>
                <option value="2.1">other</option>
            </select>
        </td>
    </tr>
    <tr>
        <th>
            <label for="tax_amount">TDR Amount:</label>
        </th>
        <td>
            <input type="text" name="tax_amount" id="tax_amount" value="0.00" class="field" disabled="disabled" />
        </td>
    </tr>
    <tr>
        <th>
            <label for="tdrtax_amount">Service Tax (12.36%) on TDR Amount:</label>
        </th>
        <td>
            <input type="text" name="tdrtax_amount" id="tdrtax_amount" value="0.00" class="field" disabled="disabled" />
        </td>
    </tr>
    <tr>
        <th>
            <label for="total_amount">Grand Total:</label>
        </th>
        <td>
            <input type="text" name="total_amount" id="total_amount" value="0.00" class="field" disabled="disabled" />
        </td>
    </tr>
</table>
</form>

JS

var calcObject = {
  amountNull: '0.00',
  amountTax: '0.00',
  amountTDRTax: '0.00',
  amountTotal: '0.00',

run: function () {
    var amount = $('#amount').val();
    var tax = $('#tax').val();
    var included = $('#tax_included').is(':checked');
    if (amount !== '' && tax !== '') {
        if (included) {
            var amountNew = amount / ((tax / 100) + 1);
            calcObject.amountTax = parseFloat(amount) - parseFloat(amountNew);
            calcObject.amountTDRTax = (amountTax * 12.36) / 100;
            calcObject.amountTotal = amountNew.toFixed(2);

        } else {

            calcObject.amountTax = (amount * tax) / 100;

            calcObject.amountTotal = parseFloat(amount) + parseFloat(calcObject.amountTax) + parseFloat(calcObject.amountTDRTax);
        }

        $('#tax_amount').val(parseFloat(calcObject.amountTax).toFixed(2));
        $('#tdrtax_amount').val(parseFloat(calcObject.amountTDRTax).toFixed(2));
        $('#total_amount').val(parseFloat(calcObject.amountTotal).toFixed(2));
    } else {

        $('#tax_amount').val(calcObject.amountNull);
        $('#tdrtax_amount').val(calcObject.amountNull);
        $('#total_amount').val(calcObject.amountNull);
    }

  }
};


$(function () {

$('#amount').keyup(function () {
    calcObject.run();
});

$('#tax_included').click(function () {
    calcObject.run();
});

$('#tax').change(function () {
    calcObject.run();
});

$('#tdrtax_amount').change(function () {
    calcObject.run();
});

});