Ajax on success result submit form and let the servlet handle the response

I have this ajax code that if the data is true it will show a modal if it is false it will submit the form/page and let the servlet in that form handle everything. I want that page to reload/ to redirect to another page from servlet..

 $("#UploadFileExcel").submit(function (event) {
            var page = document.getElementById('UplaodFilePage').value;
            var year = document.getElementById('year').value;
           event.preventDefault();
 $.ajax({
                url: "UploadCheckerServlet",
                type: 'POST',
                dataType: "JSON",
                data: {
                    censusYear: 2018,
                    page: page
                }, success: function (data) {
                    alert(data);
                    if (data === true) {
                        alert("lalala" + data);
                        $("#ShowSheets").modal("show");
                    } else if (data === false) {
                        alert("PAGE");
                         alert(this);
                        alert(year);
                          $(this).submit();
                    }
                }, error: function (XMLHttpRequest, textStatus, exception) {
                    alert(XMLHttpRequest.responseText);
                }
            });

        });

I already try bind and unbind from other questions but it still wont work.

The code works either submitting form even if should not, i tried to put the event.preventDefault(); inside the if statement but it still submits while when it is outside it wont submit form