Javascript – disable disabled form

I have this feature where it checks the data to get out of the page, what happens is that some data looks like this disabled I can not verify the data according to the data entered.

  $(function () {
    var init_form = $('#Novo').serialize();
    $(':submit').click(function () { window.onbeforeunload = null; });

        window.onbeforeunload = function () {
        var check_form = $('#Novo').serialize();
        console.log(init_form);
        console.log(check_form);
        if (check_form === init_form) return null;
        return 'Os dados do formulário não foram salvos, deseja permanecer nesta página?';
    };
});

I tried to insert this line into the method $("#Novo :input").prop('disabled', false); but it did not work either.

 $(function () {
    var init_form = $('#Novo').serialize();
    $(':submit').click(function () { window.onbeforeunload = null; });
         $("#Novo :input").prop('disabled', false);
    window.onbeforeunload = function () {
        var check_form = $('#Novo').serialize();
        console.log(init_form);
        console.log(check_form);
        if (check_form === init_form) return null;
        return 'Os dados do formulário não foram salvos, deseja permanecer nesta página?';
    };
});

How can I ensure that all data is checked, regardless of whether it is a property? disabled or readonly is like true,