Auto calculate input fields with comma while typing

Question

I have a set of input fields that automatically calculate the sum and product based on the users input. I want to work on the part wherein it will automatically add a comma too and still got the right sum while typing. Here is what I have so far.

<table>
    <tr>
    <td><input class="cell3" type="text" name="com1" id="com1" value=""></td>
    <td><input class="cell3" type="text" name="com2" id="com2" value=""></td>
    <td><input class="cell3" type="text" name="com3" id="com3" value=""></td>
    <td><input class="cell3" type="text" name="com4" id="com4" value=""></td>
    <td><input class="cell3" type="text" name="com5" id="com5" value=""></td>
    </tr>
 </table>

JScript

$(document).ready(function () {
        $(this).keyup(function aa() {

            $("input[name='com2']").each(function (index) {
                var com1 = $("input[name='com1']").eq(index).val();
                //var com2 = $("input[name='com2']").eq(index).val();
                var com2 = parseFloat(com1) * 0.15;

                if (com1 == "") {
                    com2 = 0;
                }

                if (com2 == "") {
                    com1 = 0;
                }

                else {
                    var com1 = parseFloat(com2) * 0.15;
                }

                if (!isNaN(com2)) {
                    $("input[name='com2']").eq(index).val(com2.toFixed(2));
                }

            });


            $("input[name='com3']").each(function (index) {
                var com1 = $("input[name='com1']").eq(index).val();
                var com2 = $("input[name='com2']").eq(index).val();
                var com3 = parseFloat(com1) - parseFloat(com2);

                if (com1 == "") {
                    com2 = 0;
                }

                if (com2 == "") {
                    com1 = 0;
                }

                else {
                    var com1 = parseFloat(com2) * 0.15;
                }

                if (!isNaN(com3)) {
                    $("input[name='com3']").eq(index).val(com3.toFixed(2));
                }

            });

            $("input[name='com4']").each(function (index) {
                var com3 = $("input[name='com3']").eq(index).val();
                //var com2 = $("input[name='com2']").eq(index).val();
                var com4 = parseFloat(com3) * 0.12;

                if (com3 == "") {
                    com4 = 0;
                }

                if (com4 == "") {
                    com3 = 0;
                }

                else {
                    var com4 = parseFloat(com3) * 0.12;
                }

                if (!isNaN(com4)) {
                    $("input[name='com4']").eq(index).val(com4.toFixed(2));
                }

            });


            $("input[name='com5']").each(function (index) {
                var com3 = $("input[name='com3']").eq(index).val();
                var com4 = $("input[name='com4']").eq(index).val();
                var com5 = parseFloat(com3) + parseFloat(com4);

                if (com1 == "") {
                    com5 = 0;
                }


                else {
                    var com5 = parseFloat(com3) + parseFloat(com4);
                }

                if (!isNaN(com5)) {
                    $("input[name='com5']").eq(index).val(com5.toFixed(2));
                }

            });


        });

        window.onload = aa();
    });

and here's a fiddle for a demo : https://jsfiddle.net/abopmagd/ any help would be much appreciated. Thank you!