Add and subtract values with jQuery

Need Help with following piece of jQuery code;

What I'm trying to do is;

1. add Amount into Total
2. when amount added Checkbox value get double
3. If checkbox state change, checkbox Updated value minus or add into Total accordingly
4. if Amount minus from Total, checkbox value change back to original
5. If checkbox state change, checkbox Updated value minus or add into Total accordingly

Following is the piece of jQuery Code

$('#Addcar').on('click', function() {
if($(this).html()=='Add') {
    $(this).html('Remove');
    var tot = parseFloat($('#TotalAmount').val()) + parseFloat($('#QuoteAmount').val());
    var totcan = parseFloat($('#Cancelation').val()) + 2;
    $('#TotalPrice').val(tot);
    $('#Cancelation').val(totcan);
} else {
    $(this).html('Add');
    var tot = parseFloat($('#TotalAmount').val()) - parseFloat($('#QuoteAmount').val());
    var totcan = parseFloat($('#Cancelation').val()) - 2;
    $('#TotalPrice').val(tot);
    $('#Cancelation').val(totcan);
}
});

$('#Cancelation').change(function(){
if($(this).is(':checked')){
    total = parseFloat($('#TotalAmount').val()) + Number($(this).val());
} else {
    total = parseFloat($('#TotalAmount').val()) - Number($(this).val());
}
$('#TotalPrice').val(total);
});

Here is the fiddle which explains better;

http://ift.tt/1RQN89w

Thanks for all the help

Regards.