protected void downloadFile(int fileId)
        {
            var con = new SqlConnection(ConfigurationManager.ConnectionStrings["db_conn_1"].ConnectionString);
            con.Open();

            SqlCommand com = new SqlCommand("select name,type,data from  Attachements where id=@id", con);
            com.Parameters.AddWithValue("id", fileId);
            SqlDataReader dr = com.ExecuteReader();


            if (dr.Read())
                try
                {
                    Response.Clear();
                    Response.Buffer = true;
                    Response.ContentType = dr["type"].ToString();
                    Response.AddHeader("content-disposition", "attachment;filename=" + dr["name"].ToString());     // to open file prompt Box open or Save file         
                    Response.Charset = "";
                    Response.Cache.SetCacheability(HttpCacheability.NoCache);
                    Response.BinaryWrite((byte[])dr["data"]);
                    Response.End();                     
                }
                catch (Exception e)
                {
                }
                finally
                {
                    con.Close();
                }
        }