private void DownloadFile()
{
    Response.ContentType = ContentType;
    Response.AppendHeader("Content-Disposition",
                    "attachment; filename=myFile.txt");
    Response.WriteFile(Server.MapPath("~/uploads/myFile.txt"));
    Response.Flush();
    System.IO.File.Delete(Server.MapPath("~/uploads/myFile.txt"));
    Response.End();
}