Edit

    string ext = ".jpg";
    if (System.IO.Path.GetExtension(Request.Files[file].FileName).Length == 4 || System.IO.Path.GetExtension(Request.Files[file].FileName).Length == 5)
        ext = System.IO.Path.GetExtension(Request.Files[file].FileName);
    string name = Request.Files[file].FileName + ext;
    string path = System.IO.Path.Combine(Server.MapPath("~/uploads"), name);
    if (System.IO.File.Exists(path))
        System.IO.File.Delete(path);
    Request.Files[file].SaveAs(path);
    ViewBag.FileName = name;