How to access file on server side when auto property is false??

Hello,
I am using following js to upload the file with auto property set to false as below:

<script type="text/javascript">
        $(window).load(
    function () {
        $("#fileuploader").fileUpload({
            'uploader': '/Scripts/uploader.swf',
            'script': "@Url.Action("Add", "Order")",
            'cancelImg': '/Images/cancel.png',
            'buttonText': 'Select Image',
            'fileDesc': 'Image Files',
            'fileExt': '*.jpg;*.jpeg;*.gif;*.png',
            'multi': true,
            'auto': false         });
    }
);
</script>

In my controller Order I have Add action which is as below :

public ActionResult Add(HttpPostedFileBase fileData)  // fileData is NULL and hence cannot access file
      {   

          var fileName = @"C:\Uploads\" + System.IO.Path.GetFileName(fileData.FileName);      
          fileData.SaveAs(fileName);
          return View();
      }

If i set auto:true i get the HttpPostedFileBase object whereas if I set to false I get it null hence cannot access the file.

Please guide, what I need to do?? so that I can access the file on server when my auto property is false.??

Please help...

Best Regards,
Rohan Laghate