Download Excel - jQuery

Download Excel - jQuery

I use a jqQuery UI Dialog that collect parameters which should be posted to an aspx page that will download a pre-generated excel file  based on the report parameters. 

I already have a ReportGenerator.aspx page which when executed opens the excel file 
  String filePath ="<path>\Graph_IR_Scenarios.xlsx";
            String outputFileName = @"Graph_IR_Scenarios.xlsx";
            FileInfo fileInfo = new FileInfo(filePath);

            HttpContext context = HttpContext.Current;
            HttpResponse response = context.Response;
            response.Clear();
            response.ClearHeaders();
            response.ClearContent();
            response.ContentType = "vnd.ms-excel";
            response.AppendHeader("content-type", "vnd.ms-excel");
            response.AppendHeader("content-length", fileInfo.Length.ToString());
            response.AppendHeader("content-disposition", String.Format("attachment; filename={0}", outputFileName));
            response.TransmitFile(filePath);
            response.Flush(); // this make stream and without it open chrome save dialog
            context.ApplicationInstance.CompleteRequest(); // send headers and c# server-side code still continue
            response.End(); 

//jQuery Ajax Request
$.ajax({
            type: "POST",
            url: " http://<path>/ReportGenerator.aspx",
            contentType: "application/json; charset=utf-8",
            data: {},
            success: function (data, textStatus, xhr) {
                alert('textStatus : ' + textStatus);
                alert('xhr : ' + xhr);
            },
            error: function (xhr, textStatus, errorThrown) {
                alert('textStatus : ' + textStatus);
                alert('errorThrown : ' + errorThrown);
            }
        });

Though the request goes to the server the excel file never gets downloaded though the aspx page if executed directly works