How to avoid repeating code in if/else statement inside AJAX

Im trying to do if/else inside Ajax , but as you can see in my script I'm repeating my code and i think it is better way do archive this in one line or doing if/else before Ajax and to be honest i don't know how exactly should i do Can anyone please help me or point me in the right direction!
Thanks in advance :)

JavaScript:

function RMAfunction() {
        var model = {
            Serienummer: $("#notavailable").val(),
            SelectedSerieText: $("#ddlSerial option:selected").text(),
            Kundenavn: $("#Kundenavn").val(),
            Ordrenummer: $("#Ordrenummer").val()
            }
            if (model.Serienummer === 'not available') {
                $.ajax({
                    type: 'POST',
                    url: '@Url.Action("ProcessRequestRMA", "Account")',
                    dataType: 'json',
                    data: {
                        Serienummer: model.Serienummer,
                        Kundenavn: model.Kundenavn,
                        Ordrenummer: model.Ordrenummer,
                    },
                    success: function (status) {
                        if (status) {

                            status.Serienummer = model.Serienummer;
                            status.Kundenavn = model.Kundenavn;
                            status.Ordrenummer = model.Ordrenummer;
                        }
                        else {
                            alert("Something Wrong");
                        }
                    },
                    error: function () {
                        console.log('something went wrong - debug it!');
                    }
                });
            }
            else {
                    $.ajax({
                    type: 'POST',
                    url: '@Url.Action("ProcessRequestRMA", "Account")',
                    dataType: 'json',
                    data: {
                        Serienummer: model.SelectedSerieText,
                        Kundenavn: model.Kundenavn,
                        Ordrenummer: model.Ordrenummer
                    },
                    success: function (status) {
                        if (status) {
                            status.Serienummer = model.SelectedSerieText;
                            status.Kundenavn = model.Kundenavn;
                            status.Ordrenummer = model.Ordrenummer;     
                        }
                        else {
                            alert("Something Wrong");
                        }
                    },
                    error: function () {
                        console.log('something went wrong - debug it!');
                    }
                });

            }
}