Filling the another input field based on the selection of check box

Question

I just want to auto fill input fields based on the selection of checkbox. Below is the code i am using. Its working fine but the problem is that i want to fill the input field only if the user checked the checkbox. if the user unchecked the check box again i want to remove the values that filled by the selection.

<script>
    $('.dtgPaymentDetails').change(function () {

        var flag = false;
        var receiptid = $(this).attr("receiptid");
        var receiptamount = $(this).attr("receiptamt");
        var totalamount = $("#txtTotatAmount").val();
        if (isNaN(parseInt(totalamount)))
        {
            totalamount = 0;
        }
        totalamount = parseInt(totalamount) + parseInt(receiptamount);
        $("#txtTotatAmount").val(totalamount);
        $("#txtNetAmount").val(totalamount);
    });

</script>

Answer 1

You need to check value is checked are not.

<script>
    $('.dtgPaymentDetails').change(function () {

        if($(this).is(":checked")) {
            var flag = false;
            var receiptid = $(this).attr("receiptid");
            var receiptamount = $(this).attr("receiptamt");
            var totalamount = $("#txtTotatAmount").val();
            if (isNaN(parseInt(totalamount)))
            {
                totalamount = 0;
            }
            totalamount = parseInt(totalamount) + parseInt(receiptamount);
            $("#txtTotatAmount").val(totalamount);
            $("#txtNetAmount").val(totalamount);
        } else {
            $("#txtTotatAmount").val("");
            $("#txtNetAmount").val("");
        }
    });

</script>